Fifty-Five Years After the 1970 UNESCO Convention on the Means of Prohibiting and Preventing the Illicit Import, Export and Transfer of Ownership of Cultural Property: Hiccups and Challenges

Abstract

The 1970 UNESCO Convention on the Means of Prohibiting and Preventing the Illicit Import, Export and Transfer of Ownership of Cultural Property remains the cornerstone international instrument governing the restitution of cultural objects in peacetime. This article critically assesses the extent to which the Convention still fulfils its objectives more than five decades after its adoption. Through a legal and analytical examination of its core provisions, national implementation practices and selected judicial decisions, the study identifies several structural weaknesses that limit its effectiveness. These include the use of broad and indeterminate language, the lack of enforcement mechanisms, significant divergences between domestic legal frameworks and persistent challenges relating to provenance, scope, non-retroactivity and the interpretation of good faith. The article further discusses the extent to which States have attempted to mitigate these shortcomings through complementary legislative, judicial and diplomatic measures. It concludes that although the Convention retains important symbolic and normative value, its operational limitations continue to impede the effective recovery of cultural heritage. The article argues that a carefully designed amendment process, coupled with strengthened bilateral or regional cooperation, could enhance the Convention’s future implementation.

1. Introduction

The illicit trade in cultural property represents a persistent challenge for the preservation of cultural heritage. In response, UNESCO adopted the 1970 Convention on the Means of Prohibiting and Preventing the Illicit Import, Export and Transfer of Ownership of Cultural Property, establishing an international framework aimed at curbing trafficking, facilitating return, and promoting cooperation among States Parties. Despite its broad ratification, the practical effectiveness of the Convention has been the subject of ongoing debate. Scholars have highlighted issues such as the vagueness of key provisions, inconsistencies in national implementation, and gaps in enforcement mechanisms [1,2,3]. Moreover, challenges arise regarding the limited scope of protected cultural property, the treatment of objects from illicit excavations, the burden of proof during the return process and compensation to bona fide purchasers [4,5]. The assessments of UNESCO emphasize continuing difficulties related to documentation standards, export certification practices, and administrative capacity across States Parties (UNESCO Information Kit; Fact Sheets).

Although much of the existing literature has focused on the historical and normative aspects of the Convention, fewer studies have examined how its mechanisms operate in practice more than fifty years after its adoption. This study seeks to address this gap and offers a critical analysis of the Convention’s operational strengths and limitations. The central research question guiding the study is therefore the following: to what extent does the 1970 UNESCO Convention effectively prevent illicit trade and facilitate the restitution of cultural objects under current state practice, and where do its operational limitations most clearly manifest? By analyzing key provisions, case studies, national legislation, and documented restitution efforts, the research identifies recurrent structural and procedural challenges and considers potential avenues for strengthening implementation, including clearer standards, improved documentation practices, and more coherent cooperative arrangements among States Parties.

The article is organized to provide a systematic analysis of the 1970 UNESCO Convention. It begins with a methodology section that explains the legal and comparative approach employed to examine relevant case studies, national legislation, and restitution practices. This is followed by the presentation of results and discussion, which situate the Convention within its historical context, review its key provisions, and outline the obligations of both exporting and importing States. The discussion further identifies operational weaknesses, recurring challenges in enforcement, and areas where implementation could be strengthened. Finally, the article offers recommendations and draws conclusions, integrating theoretical insights with practical implications to provide a comprehensive understanding of the Convention’s effectiveness and ongoing challenges.

2. Materials and Methods

This study takes a legal and analytical approach, combining doctrinal, comparative, and interpretative methods. The aim is not only to examine the formal provisions of the 1970 UNESCO Convention, but also to understand how these provisions function in practice. The approach focuses on the interaction between international legal norms and domestic legal systems, and pays particular attention to recurring gaps or ambiguities, such as the Convention’s scope limitations, non-retroactive effect, and the treatment of good faith and compensation.

The research draws on a combination of primary and secondary sources. Primary materials include the text of the 1970 UNESCO Convention, relevant judicial decisions from countries with significant restitution activity (United States, United Kingdom, Italy, Greece, China, and the Netherlands), UNESCO operational guidelines, and documentation of national and international practice. Secondary sources include scholarly articles, books, and case analyses that assess the legal, institutional, and practical dimensions of the Convention’s operation. Countries were selected for their cultural significance, frequency of restitution cases, and representation of common law and civil law traditions. Judicial decisions considered span from the 1970s to the 2020s allowing the study to capture both historical and contemporary developments.

Analysis was conducted through doctrinal examination to interpret legal texts, coupled with comparative evaluation to see how different legal systems incorporate the Convention’s principles. Interpretative methods were applied to examine judicial reasoning, the application of lex originis, and the treatment of good faith and compensation. Restitution cases were used as illustrative examples to show how legal theory translates into practice and to highlight recurring challenges and inconsistencies.

This study is primarily doctrinal and analytical in nature and therefore relies exclusively on publicly accessible legal sources, scholarly commentary, and national implementing legislation. As a result, it does not incorporate empirical data from field practitioners such as customs authorities, law-enforcement agencies, or museum acquisition committees. Moreover, the selection of jurisdictions, although representative of key legal approaches and implementation challenges, is not exhaustive and necessarily reflects a limited geographical scope. The absence of comprehensive and comparable quantitative datasets on restitution claims, implementation outcomes, or market practices further constrains the possibility of assessing the Convention’s effectiveness in measurable terms. These limitations do not detract from the value of the analysis but indicate the need for complementary empirical research in future studies, particularly in relation to the operational impact of the Convention in diverse national contexts.

3. Results

The analysis of the practical implementation of the 1970 UNESCO Convention reveals several recurring challenges that limit its effectiveness. Key provisions, such as those on export certificates (Article 6) and import restrictions (Article 7), remain vague, resulting in significant differences in interpretation and application among States Parties. For example, antiquities originating from illicit excavations are not recorded, making restitution difficult, while inventories of public institutions are often incomplete or inaccessible. This creates gaps in protection, as unregistered objects can circulate on the art market with little oversight.

The implementation of the Convention depends on national authorities. Some States maintain strict legislation and specialized authorities to monitor export and import of cultural property, while others lack resources or political will, allowing illicit trafficking to persist. Similarly, the regulation of the art market is inconsistent: public museums may face strict acquisition rules, whereas private museums and collectors are less regulated, creating opportunities for circumvention.

Other practical limitations include the non-retroactive application of the Convention, which excludes objects trafficked before a State’s ratification, and the ambiguous rules on compensation and good faith, which leave both source countries and possessors uncertain about their rights and obligations. While bilateral agreements and international cooperation can partially address these gaps, the overall framework lacks standardization, leading to fragmentation in practice.

These findings indicate that, despite widespread ratification, the Convention’s impact is constrained by imprecise provisions, inconsistent national implementation, and the absence of uniform monitoring or enforcement mechanisms. These challenges point to a clear need for reform: clearer standards, standardized documentation, more coordinated international procedures, and potentially targeted amendments or agreements are necessary to strengthen the Convention’s ability to prevent illicit trafficking and ensure effective restitution of cultural property.

4. Discussion

4.1. Historical Context

The 1970 UNESCO Convention arose in response to a deeply troubling reality: the unchecked growth of the illicit trade in works of art, the intensifying demands for the restitution of cultural property—particularly items wrongfully removed during the colonial era [1] (p. 30)—and the mounting alarm over the infiltration of unlawfully trafficked cultural objects into legitimate markets. By the 1960s, it was increasingly acknowledged that such unlawful circulation severely depleted the cultural heritage of source nations and that only international cooperation could effectively address the problem [6] (p. 97). Within this climate, the General Conference of UNESCO, meeting in Paris, adopted on 14 November 1970 the Convention on the Means of Prohibiting and Preventing the Illicit Import, Export and Transfer of Ownership of Cultural Property. Entering into force on 24 April 1972, the Convention represented the first ad hoc international legal instrument devoted to the protection of cultural heritage and the suppression of illicit trade in cultural property [7] (p. 2).

The 1970 UNESCO Convention, as an instrument of public international law, concerns exclusively the cultural property of States and not that of private individuals [8] (p. 159). Disputes falling within its scope are disputes between States Parties, which, according to its provisions, are to be resolved primarily through diplomatic channels, or, if deemed necessary, through judicial means [9] (p. 4). By ratifying the Convention, States are obliged to adapt their domestic legislation to its requirements. The Convention rests on three principal “pillars”: preventive measures at the national level to effectively combat the illicit trafficking of cultural objects; mechanisms for the restitution and return of antiquities; and cooperation among States [10] (p. 63).

4.2. Key Provisions

4.2.1. Purpose

The 1970 UNESCO Convention was intended to limit the illicit circulation of cultural property and to strengthen mechanisms for its restitution. In pursuit of this aim, the Convention establishes a minimal international framework of cooperation, within which States Parties assume reciprocal responsibilities and obligations to protect cultural objects against theft, unlawful excavation, illicit import, export, trafficking, and transfer of ownership. At the same time, the Convention seeks to lend support to the individual efforts of States in preserving their cultural heritage [11] (p. 541).

Under the Convention, achieving this purpose is of particular significance because, according to Article 2, the illicit trafficking of cultural property constitutes one of the principal causes of the degradation of the cultural heritage of source countries, depriving them of essential elements of cultural expression, development, and identity. The knowledge derived from careful, scientifically grounded recovery and study of archaeological material and cultural property generally must be protected [1] (p. 34). The interpretation and understanding of cultural objects are possible only when they are examined in connection with their place of origin and the specific conditions under which they were discovered. By contrast, when cultural objects are removed illicitly from their functional and historical context, they are stripped of any capacity for meaningful study or interpretation [8] (p. 160).

4.2.2. Scope

The cultural property falling within the scope of the Convention may possess either religious or secular significance. They are regarded as cultural property because of their importance for archaeology, prehistory, history, philology, art, or science [1] (p. 38). The Convention provides a non-exhaustive, illustrative enumeration of the categories of protected cultural property. These categories include the results of excavations, items derived from the dismantling of monuments or archaeological sites, antiquities such as inscriptions, coins, and seals over 100 years old, objects of ethnological, artistic, or historical interest, rare manuscripts, archetypes, early printed books, documents and editions of particular significance, rare collections, and specimens of fauna, flora, or minerals, as well as anatomical specimens and objects of paleontological interest [12] (p. 377).

Each State is free and responsible for determining which cultural property constitutes part of its cultural heritage. An object qualifies as part of a State’s cultural heritage if it is the product of the individual or collective genius of its nationals, or if it was created within its territory, whether by foreign nationals or stateless persons. Additionally, an object may be regarded as cultural property if it was discovered within the national territory of the State concerned. In these cases, a special relationship exists between the State and the cultural object [1] (p. 38). However, such an inseverable link between a State and a cultural object is not always required. Under cases (c), (d), and (e) of Article 4, a State may classify as cultural property an object it has acquired, whether through archaeological, ethnological, or natural science missions, or through exchange, donation, or lawful purchase [13] (p. 226).

The concept of a link between a State and a cultural object tends to be applied flexibly. A notable example is the case of Beyeler v. Italy, in which the European Court of Human Rights (ECtHR) rejected Beyeler’s claim that a Van Gogh painting lacked any connection to Italian cultural heritage due to the artist’s Dutch origin. The Court emphasized that it is within the States’ discretion to determine which objects constitute their national cultural heritage, thereby affirming their sovereign right over their cultural property, as also enshrined in Article 4 of the 1970 Convention [14] (p. 361). Within this framework, a State enjoys the inalienable right to designate certain objects as part of its cultural property, to declare them inalienable, and to prohibit their export. This right, enshrined in Article 13 (d) of the Convention, must be recognized and respected by all other States Parties [13] (p. 227).

4.2.3. The Role of Competent Authorities

States Parties to the Convention are obliged to establish national authorities staffed with adequate and specialized personnel, tasked with the protection of their cultural heritage, specifically against illicit import, export, and transfer of ownership. The Convention does not prescribe the number of such authorities; however, they must be sufficient to fulfil the functions outlined in Articles 5 and 14. These include the drafting of relevant legislation; the preparation and maintenance of registers of cultural property; the establishment, promotion, and development of scientific and technical institutions necessary for the preservation and display of cultural property; the organization and supervision of archaeological excavations; ensuring in situ conservation of findings; the adoption of codes of conduct; the design and implementation of educational programmes to foster respect for cultural heritage; and the public disclosure of any instances of missing cultural property. Despite variations that may exist among national authorities of different States Parties, these bodies are required to direct their efforts toward the achievement of the Convention’s objectives [1] (p. 41).

4.2.4. Obligations of the Exporting State

Among the obligations of States Parties are (a) the introduction of an export certificate for cultural property, (b) the prohibition of exporting cultural property without such a certificate, and (c) the publication of this prohibition by appropriate means (Article 6) [1] (p. 44).

The Export Restriction on Cultural Property and the Establishment of an Export Certificate

The overall purpose of this provision is not to restrict the export of cultural property but to regulate it through a lawful procedure. Article 6(b) clarifies that the export of cultural property is prohibited without the export certificate. This certificate contains all essential information that must accompany any cultural object being exported as part of the State’s cultural heritage. It is recommended that the certificate include photographs, a description of the object, and details concerning the destination State and the period of validity of the certificate. In cases where a cultural object is sent for exhibition, scientific, or educational purposes, the certificate may be issued with temporary validity [11] (p. 548). This process provides the authorities with the opportunity to prevent the export of an object and to obtain information about the intended destination of the exported cultural property. At the same time, it offers the prospective purchaser the benefits associated with acquiring a cultural object in good faith [13] (p. 135).

The UNESCO, in collaboration with the World Customs Organization (WCO), has developed a standard form for the export of cultural property, the Model Export Certificate for Cultural Objects (MEC). To date, however, States Parties to the Convention have not adopted a uniform, single-format export certificate. At the Union level, Member States, pursuant to Regulation 116/2009, follow a uniform system of preventive controls for the export of cultural property. In order for a cultural object to be exported outside the customs territory of the European Union, it must be accompanied by two standardized documents: an export licence and an export declaration. This approach establishes a common standard for all Member States, aimed at ensuring a high level of protection for cultural property within the internal market [15] (p. 462).

The widespread adoption of a common model, such as MEC, would facilitate the prompt identification and tracking of cultural objects, while significantly reducing administrative burdens for both exporters and customs authorities. UNESCO and the WCO recommend adopting the model in full or in part, adapted as necessary to national standards for export certificates. Furthermore, it would facilitate the competent authority in maintaining records of the certificates it issues, as well as of applications for the export of cultural property that are refused. Maintaining such records is particularly valuable in cases of forgery or falsification of an existing certificate [16]. A potential amendment to the 1970 UNESCO Convention could make the adoption of a standardized, uniform export certificate mandatory for all States Parties, ensuring consistency and reducing gaps in enforcement. At the same time, in order to avoid a rigid uniformity that might discourage participation, States Parties could be allowed limited national adaptations, both promoting flexibility and maintaining overall coherence.

The Importance of Publicity and Documentation

The prohibition on the export of a cultural object should be accompanied by the widest possible publicity. Moreover, if the State of origin discovers that a cultural object has been exported in violation of its national legislation, it should make the incident public. This provision serves a threefold purpose: it aims to limit the number of potential buyers for such objects, enables experts (and the general public) to inform States of the object’s location, and ensures that the publication of a cultural object may invalidate any claims by a purchaser for compensation based on good faith. A purchaser acting in good faith is expected to exercise due diligence by consulting databases where endangered or missing cultural objects are recorded. Consequently, the likelihood increases that the State deprived of possession can recover the object without paying any compensation to its current holder. The effective and widespread publicity is conducted through mass media and the internet, potentially within the framework of an international campaign. Specialized services and databases, such as INTERPOL’s Works of Art or Art Loss Register (ALR), exist to facilitate this objective [1] (p. 43).

In order to detect the loss of a cultural object, Member States must have recorded their protected items. Competent authorities are required to compile national registers of protected cultural property and to update them regularly. This provision is particularly significant, as it extends not only to public collections but also to private ones. Clearly, it is extremely difficult for a private collector or museum to fully publicize their holdings. To address this, States should encourage private individuals, either through tax incentives or other measures, to register significant cultural objects in databases accessible to the competent authorities [17] (p. 50).

At the same time, cataloguing serves as evidence in claims concerning cultural property. Particularly in cases of theft, registers can provide detailed descriptions and act as proof of the provenance of a cultural object [18] (p. 25). During the recording process, it is useful to apply the system proposed by the Object ID standard. This is a standardized object identity document in which the description of cultural property follows a uniform template with specific information. The required information includes the name of the object, its location, its provenance, the catalogue number, a description of the object, a brief history of ownership, and references where interested parties can find further information about the object [1] (p. 42).

A potential amendment to the Convention could envisage the integration of contemporary digital technologies to enhance the recording of cultural property. In this context, States Parties could register protected objects on national digital platforms, which might be interconnected at an international level to facilitate cross-checking of information and rapid notification in the event of lost or stolen items. Such registration could follow the Object ID standard, providing a uniform and structured format for key data, while still allowing States a degree of flexibility to accommodate national particularities and technological capacities.

4.2.5. Obligations of the Importing State

The Prohibition of Illicit Imports of Cultural Property

Article 7 outlines the obligations of States Parties regarding the import of cultural property. Under paragraph 7(b)(i), States Parties to the Convention are required to prohibit the import of cultural property that has been stolen from museums, religious or public monuments, or similar institutions located within the territory of another State Party to the Convention. For a cultural object to fall within the scope of this provision, it must be recorded in the registers of the institution to which it belongs. Accordingly, the provision establishes two cumulative conditions: the cultural object must originate from a cultural or religious institution or monument, and it must be duly registered [19] (p. 65).

These two conditions significantly restrict the number of protected objects. Firstly, they do not cover items originating from illicit excavations. Such objects are unknown to the State of origin and leave its territory without the knowledge of the competent authorities; consequently, it is impossible for them to have been registered prior to their unlawful removal. Secondly, the registers of cultural institutions are often incomplete or may have been lost. Moreover, many States lack the financial resources to complete such inventories or may be reluctant to undertake comprehensive cataloguing [20] (p. 342). Thirdly, the provision does not specify the precise nature of such registration. One could interpret the provision broadly, contending that a cultural object merely documented in the holdings of a museum of a State Party, without a detailed description, satisfies the requirement of specific designation. Conversely, it may be argued that registration should take the form of an inventory, that is, a concise list in which the object is recorded with the essential information identifying it, including its title, owner, dimensions, registration or catalogue number, provenance, exhibition history, relevant publications, and records of conservation or restoration. Requiring such a comprehensive description, however, could unduly narrow the scope of the provision [21] (p. 251).

The Inconsistency of Article 7(bi) with the Export Certificate Requirement

The limited scope of Article 7(bi) creates a direct inconsistency with the broader obligations established under Article 6 regarding export certificates. States Parties are not obliged to prohibit the import of every cultural object that has been exported in violation of the national legislation of the State of origin; rather, the import prohibition applies only to cultural property that has been stolen from a museum, a religious or secular public monument, or a similar institution in another State Party, and provided that such property has been registered by the institution in question. In this light, Article 6, which establishes the requirement of an export certificate, would become a provision without practical effect [1] (p. 45).

Considering that, under Article 31 of the 1969 Vienna Convention on the Law of Treaties, an interpretation that gives meaning is preferred over one that renders a provision meaningless, it follows that no provision in the Convention can contradict other provisions of the same Convention. Moreover, given that export certificates constitute a widely accepted practice today, it could be argued that if an export is deemed illegal under the regulations of the State of export, it should likewise be considered illegal by the State of import. Otherwise, treating it as lawful by the importing State would be inconsistent with the spirit of the Convention [1] (p. 35).

Given that Article 6 establishes the export certificate as the principal instrument for the lawful circulation of cultural property, the Convention could be strengthened by explicitly requiring States Parties to accept the export State’s national legislation determining the legality of a transfer. In this regard, a cultural object exported without the requisite certificate should likewise be considered illicit by the importing State, irrespective of whether it originates from a public or private collection. Such an amendment would reinforce mutual trust among States Parties and close existing loopholes that allow inconsistencies between national systems to undermine the effectiveness of the Convention.

4.2.6. The Regulation of the Art Market

States Parties are under an obligation to prevent museums and other cultural institutions from acquiring cultural objects originating in another State Party that have been unlawfully exported after the entry into force of the Convention. Article 7(a) embodies a compromise between, on the one hand, a moderate approach that would require, inter alia, the dissemination of the text of the Convention to museums and other institutions in an effort to secure their adherence to the principles of ethical acquisition, and, on the other, a stricter amendment that would have prohibited museums from acquiring any cultural object lacking an export certificate [17] (p. 57).

It is of particular importance to establish a consistent regulatory framework that applies equally across all actors in the art market, thereby preventing disparities that would privilege certain parties over others. Allowing museums to be bound by strict acquisition standards, while private collectors remain unregulated, creates a distortion that undermines the objectives of the Convention. If museums are prohibited from acquiring cultural objects lacking full provenance documentation, but private collectors face no such constraint, the latter would enjoy a comparative advantage, to the detriment of museums and other cultural institutions [1] (p. 42).

This possible imbalance underscores the broader necessity for effective regulation of art market transactions as a whole. In this respect, Article 13(a) obliges States Parties to take all appropriate measures to prevent the transfer of ownership of cultural property that is likely to have been illicitly imported or exported [13] (p. 238). This is the only reference in the entire Convention to the notion of “transfer of ownership.” The Convention, however, provides no guidance as to what types of transfers may be deemed to promote or facilitate the illicit movement of cultural objects. The absence of clarification on this point risks generating divergent interpretations among States Parties [11] (p. 554). It is therefore left to domestic legal systems to determine how best to regulate transactions that contribute to the illicit trade in cultural property. Within this framework, States Parties could, for instance, impose upon dealers the obligation to maintain detailed registers recording the provenance of each cultural object, the names and addresses of suppliers, a description and the sale price of each item, as well as to notify purchasers of any applicable export restrictions attached to the cultural property concerned [1] (p. 61).

4.2.7. The Restitution Procedure

The State into which a cultural object has been unlawfully imported is under an obligation to notify the State of origin of its presence and to take appropriate measures for the seizure and restitution of the illicitly transferred item. Nevertheless, the initiation of restitution proceedings is contingent upon a formal request by the State of origin. Such a request typically concerns an object belonging to the requesting State itself; however, in the absence of an express prohibition, the State of origin may also submit a claim on behalf of a private owner whose property has been stolen. According to the Convention, the restitution of unlawfully transferred cultural objects may be effected in two ways: either through diplomatic channels or by means of a legal action for recovery [13] (p. 232–233).

Article 13(b) obliges States Parties to ensure that their competent services cooperate so as to facilitate the prompt return of illicitly exported cultural property to its rightful owner. The notion of “owner” must be interpreted in light of the spirit of the Convention and, in particular, in relation to Article 13(d). Accordingly, the term should be understood to designate exclusively the State from which the cultural object was unlawfully removed, as only the State of origin is vested with the sovereign right to declare its cultural property inalienable [17] (p. 83).

It may be contended that this provision does not substantively advance beyond the obligations already incumbent upon States under their respective domestic legal systems. Where an object is classified as unlawfully exported, its restitution should, in principle, be effected pursuant to the laws of the State concerned. The Convention, however, remains silent as to the specific measures that States are required to adopt in this context. Such measures might encompass, inter alia, the facilitation of the return of the cultural object to the State of origin, or, at a minimum, the retention of the object within a given jurisdiction pending judicial adjudication. A more rigorous and precise drafting of the provision would have been preferable, as it could have furnished explicit guidance on the modalities of seizure or confiscation, as well as on the procedural mechanisms designed to ensure effective recourse before national courts [1] (p. 50).

Although restitution proceedings are typically pursued through diplomatic channels, States Parties to the Convention are obliged to accept legal claims brought by the lawful owners seeking the return of stolen or lost cultural property. The Convention does not seek absolute uniformity in legal systems; accordingly, it does not prescribe the procedural modalities of such claims, the requisite documentation, or questions of jurisdiction and applicable law. Viewed in light of the Convention’s broader objectives, States Parties appear to be required to assess the illicit nature of an export in accordance with the law of the requesting State (lex originis), since the domestic legislation of the States to which cultural objects are illicitly transferred generally does not favour their restitution to the State of origin. By contrast, the application of the law of the State where the cultural object is situated (lex rei sitae) would render restitution to the State of origin difficult, if not practically impossible [3] (p. 140).

A possible amendment to the Convention could envisage the establishment of a common framework of minimum procedural standards for the seizure and restitution of unlawfully exported cultural objects. Such a framework could explicitly require States Parties to apply the law of the State of origin (lex originis) when determining the illicit nature of an export, while allowing them sufficient flexibility to regulate the procedural aspects domestically, whether through administrative or judicial means. This proposal, which is further developed in the subsequent analysis, would enhance consistency during restitution processes.

4.2.8. Sanctions

Criminal and administrative sanctions are addressed in Articles 8 and 10 of the Convention. These provisions do not specify the range or severity of penalties, but rather define the acts that are considered punishable. Under Article 8, States Parties are required to impose sanctions on anyone who: (a) exports cultural property without the appropriate export certificate; (b) imports cultural property stolen from a museum, religious or secular public monument, or similar institution located in the territory of another State Party; or (c) violates the obligations under Article 7(b)(ii) regarding the seizure, notification, and restitution of cultural property [22] (p. 23).

Article 10 introduces a fourth punishable act concerning art dealers. Failing to keep records documenting the provenance of each cultural object, the details of the supplier, the sale price, and the circumstances of its export from the State of origin may attract administrative or criminal sanctions. This provision is particularly important because the confidentiality obligations and duties to protect client privacy can, in practice, facilitate illicit activity. In some instances, records are deliberately not kept to help clients legitimize cultural objects or launder money [1] (p. 62). For this reason, the provision could benefit from a broader scope, applying generally to all sellers of cultural property.

The Convention does not prescribe the specific nature or severity of sanctions, leaving States Parties with broad discretion to adopt measures they deem effective in fulfilling the Convention’s objectives. As a result, there is significant divergence in the regulatory and enforcement frameworks implemented across different States Parties. This lack of uniformity creates potential gaps in enforcement, as individuals or entities may exploit these discrepancies by transferring their activities to jurisdictions with more lenient penalties or weaker regulatory oversight. Such variations undermine the effectiveness of the Convention, allowing illicit practices to persist despite the formal obligations imposed on States Parties [1] (p. 54).

Given the challenges posed by this weakness, States Parties might consider addressing the gap through targeted bilateral or regional agreements. Such agreements could explicitly reference the principles and obligations of the 1970 UNESCO Convention while incorporating criminal law provisions inspired by the Council of Europe Convention on Offences relating to Cultural Property. Integrating these commitments into broader frameworks, such as trade or cultural cooperation agreements, would enhance legal coherence and provide effective enforcement mechanisms. In particular, these arrangements could criminalize the entire illicit chain of a cultural object, from illegal excavation through export, trafficking, and ultimately unlawful acquisition. This would, for example, ensure that art dealers maintain proper records and that violations concerning the unlawful export or import of cultural property are subject to enforceable penalties, thereby creating a comprehensive framework for prosecution and deterrence.

4.3. Weaknesses of the Convention

4.3.1. The Lack of Precision in the Provisions

The Convention has been ratified both by “source countries,” such as Cyprus and Greece [23] (p. 60 and 90), and by major art-importing States, including Germany, the Netherlands, and Switzerland [24] (p. 2). The participation of so-called “market States” constitutes a significant achievement, as accession implies recognition of the right of source countries to assert claims over their cultural heritage [25] (p. 772). This accomplishment should not be underestimated; rather, it must be borne in mind when examining the provisions of the Convention, which were designed as a compromise between two diametrically opposed positions [26] (p. 29–30).

It is precisely this effort to reconcile conflicting interests that explains why a number of provisions are deliberately couched in vague terms. The drafters sought to establish only a minimum level of protection, rather than to impose complete legislative uniformity among States Parties. While this ambiguity may have facilitated broad ratification, it has also deprived the Convention of the dynamism it might otherwise have had, allowing each State Party to transpose the obligations into its domestic legal order in whatever manner it sees fit. As a result, considerable divergences emerge in both the interpretation and implementation of the Convention across jurisdictions.

These divergences are particularly evident when contrasting different domestic approaches. Certain States, such as Italy and Greece, have adopted a stringent legislative framework, enshrining State ownership of cultural property and establishing criminal sanctions for violations concerning its circulation and export. By contrast, in other jurisdictions—most notably France—the implementation of the Convention has been subject to significant reservations. Although France places considerable emphasis on the conclusion of bilateral agreements regulating the restitution of cultural objects, its domestic legal framework imposes substantial limitations on the ability to pursue claims against bona fide possessors. In the absence of contrary provisions under a bilateral agreement, French law places the burden of proof squarely on the claimant to establish the possessor’s bad faith. In addition, the right to seek restitution of a cultural object is extinguished three years after the claimant has lost possession of the item. This restrictive approach diverges markedly from the underlying purpose of the Convention, which is designed to strengthen, rather than curtail, the claims of States of origin in recovering their cultural heritage [27] (p. 74).

The limitations of the Convention are not confined to such discrepancies in domestic implementation. A further structural weakness lies in the absence of any enforcement mechanism by which a State Party may be compelled to fulfil its obligations [17] (p. 74). Compliance is therefore left to the discretion and goodwill of the Parties themselves. In the absence of procedural safeguards, and given the vagueness and generality that characterize many of its provisions, the Convention’s binding commitments risk being rendered largely declaratory, undermining its effectiveness as an instrument of international law [28] (p. 259).

This, however, does not mean that these obligations lack legal effect for the States Parties. On the contrary, according to article 31(1) of the 1969 Vienna Convention on the Law of Treaties ‘a Treaty shall be interpreted in good faith in accordance with the ordinary meaning to be given to the terms of the Treaty in their context and in the light of its object and purpose’. In Commonwealth of Australia v. State of Tasmania, a case which did not involve the 1970 UNESCO Convention, though of a similar nature, Judge Mason noted that ‘however loosely such obligations may be defined, it is apparent that [a state], by depositing its instrument of ratification, bound itself to observe the terms of the Convention and assumed real and substantive obligations under them” [1] (p. 32).

4.3.2. The Convention’s Limited Scope

Establishing Provenance

The Convention’s scope would benefit from reconsideration in light of contemporary objectives and challenges. While innovative in the 1970s, its provisions now appear somewhat outdated and narrowly defined. Article 7(b)(i) exemplifies this limitation, requiring, first, that a cultural object originate from a cultural or religious institution or monument, and second, that it be formally documented. In practice, these requirements exclude a substantial number of cultural objects from the Convention’s protection [29] (p. 40).

This cautious approach reflects the deliberations of the Committee of Experts, which concluded that a blanket prohibition on imports would be impracticable. At the same time, the Committee recognized the necessity of preventing situations in which stolen cultural objects from one country could appear in the public collections of another. Nevertheless, the article’s strict conditions create significant obstacles for claims concerning objects that were never properly recorded due to administrative inaction. Few cultural institutions maintain comprehensive inventories, and in many cases, the claimant State may simply be unable to obtain the necessary documentation, rendering restitution effectively impossible.

The practical consequences of these limitations are illustrated by the 2013 restitution of Cypriot cultural objects from Germany. In that case, approximately 170 detached wall paintings, mosaics, and icons were returned after a seizure operation uncovered more than 5000 objects, of which roughly 350 were of Cypriot origin. Only 173 items were ultimately repatriated, as these were the only objects whose Cypriot provenance could be conclusively demonstrated by a German Byzantine studies expert, Johannes De Decker. The remaining objects required further investigation to establish whether they had indeed been removed from churches in the occupied territories. Most objects illicitly exported from the occupied part of the island were never catalogued prior to the 1974 invasion, and Cypriot authorities cannot access the occupied areas to conduct inventories or research [30].

These practical difficulties underscore the importance of allowing courts to accept indirect but reliable evidence of provenance. In such cases, ex post facto registration should be permitted: where a cultural object was not formally recorded, the claimant State ought to have the flexibility to rely on alternative evidence capable of serving the same purpose. This could include, for instance, photographs or drawings showing the object in situ, or stylistic comparisons linking it to other artefacts located within the claimant State.

The Convention could be amended to explicitly allow, in cases where a cultural object was not formally registered, the acceptance of indirect but reliable evidence to establish provenance. Incorporating this approach would provide greater flexibility in restitution proceedings, addressing the practical difficulties that arise when administrative gaps or historical circumstances have prevented proper documentation. By acknowledging the legitimacy of alternative forms of proof, the Convention would better align with its broader purpose of protecting cultural heritage, ensuring that the absence of formal records does not unduly hinder the recovery of unlawfully exported objects.

Finally, it is important to note that Article 7(b)(i) primarily addresses import restrictions rather than restitution. Any future amendment to the Convention should clarify this point, explicitly confirming that claims for the return of unrecorded objects are permissible, irrespective of the rules governing importation.

Objects from Illicit Excavations

The current wording of the Convention excludes cultural objects arising from illicit excavations from its protective scope. Such items, being unknown to the State of origin, have never been formally registered. By contrast, museum collections are catalogued, documented, and securely held; consequently, if such objects are stolen, their visibility and documentation act as a deterrent against their circulation on the art market. Items derived from illicit excavations, however, remain highly attractive to trafficking networks precisely because they lack official registration. In practice, the majority of objects appearing on the illicit market originate from such clandestine digs.

The protection of these particularly vulnerable cultural objects could be significantly strengthened through the widespread adoption of a standardized documentation system, such as the Object ID format. A potential amendment might stipulate that any cultural object, especially an antiquity, presented at customs without an Object ID and/or an export certificate should be presumed to originate from a recent illicit excavation, and therefore to have been unlawfully removed from its State of origin. The Convention should expressly mandate that customs authorities verify whether imported objects are accompanied by documentation in the form of an Object ID. The importation of any item lacking such documentation should be prohibited. Simultaneously, an object accompanied only by an import certificate, but lacking documentation confirming lawful provenance and ownership history, should prompt caution for prospective buyers. In this context, it is vital that buyers do not rely solely on the import certificate. They should undertake a thorough investigation of the object’s provenance to ensure acquisition in good faith. Such due diligence is not only a matter of legal compliance but also a fundamental aspect of ethical collecting [9] (p. 15).

The Non-Retroactive Effect of the Provisions

The 1970 UNESCO Convention contains no explicit provision addressing its retroactive applicability. In accordance with the Vienna Convention on the Law of Treaties, in the absence of a specific clause, the Convention cannot be applied retroactively; it operates only from the date of entry into force for each State Party [13] (p. 234). The 1970 Convention entered into force on 24 April 1972 and binds only those States that were parties at that time. For States acceding subsequently, the Convention becomes applicable three months after their ratification. Practically, this means that the Convention covers only cultural objects illicitly trafficked after it came into force in both the source and receiving States.

This non-retroactive effect represents a significant limitation on the Convention’s effectiveness, particularly regarding objects derived from illicit excavations [31] (p. 517). Traffickers frequently present such objects as antiquities that were allegedly discovered and traded prior to 1972. Although this date may seem distant, the competent authorities are generally unable to disprove these claims, as items from illicit excavations are unknown to the State of origin and have never been registered. In practice, authorities often lack sufficient evidence to establish the precise timing of unlawful removal [32] (p. 234). Consequently, the Convention leaves unprotected a substantial, albeit largely unidentified, number of archaeological objects that have yet to be discovered.

Moreover, the non-retroactivity of the Convention constitutes a notable disadvantage for States that experienced repeated looting in the decades preceding its entry into force [33] (p. 22). The illicit trade in cultural property flourished in the pre-1970 period due to the absence of an international legal framework. Such cases fall outside the Convention’s scope. To address these historical losses, the UNESCO Intergovernmental Committee for Promoting the Return of Cultural Property to its Countries of Origin or its Restitution in case of Illicit Appropriation (ICPRCP) was established [1] (p. 180). While serving primarily in an advisory capacity, the ICPRCP seeks practical means to facilitate negotiations for the restitution of cultural property. Its recommendations, although not legally binding, provide an important set of guidelines and solutions to help parties reach mutually acceptable agreements [1] (p. 58).

4.3.3. The Applicable Law

Several States, particularly those with heightened awareness of cultural heritage protection, had established domestic export prohibitions prior to the 1970 UNESCO Convention. Nevertheless, national legislation alone proved insufficient to safeguard and reclaim illicitly removed cultural objects at the international level. The Convention’s non-retroactive effect means that States Parties cannot assert claims over cultural objects lost before 1972, except under pre-existing domestic legal frameworks rather than under the specific provisions of the Convention [1] (p. 63). In such contexts, the application of the law of the source State (lex originis) can serve as a mechanism to circumvent the limitations imposed by the Convention’s non-retroactivity, particularly where the source State had enacted internal protections for its cultural property prior to the entry into force of international rules.

The adoption of the 1970 UNESCO Convention marked a turning point in judicial approaches to disputes involving cultural property. In the United States v. Schultz, the Court of Appeals acknowledged that, as a general principle, U.S. courts do not routinely apply foreign laws governing the export of cultural objects. Nevertheless, the Court clarified that antiquities could be claimed as stolen property if the State of origin could demonstrate that (1) the object was discovered within its territory; (2) a heritage law existed at the time, vesting ownership in the State; and (3) such law clearly established State ownership of the cultural object [34]. In this case, the U.S. art dealer Schultz acquired Egyptian antiquities in the 1990s at markedly low prices, purportedly justified by their declared undervalued status upon importation. Although Schultz was not responsible for their illicit removal from Egypt or subsequent illegal import into the United States, the Court of Appeals concluded that, having sold the items at a significant profit, he was aware of their true value. Consequently, the Court applied Egyptian law concerning the acceptance of stolen antiquities trafficked through illegal international channels [35].

This case significantly influenced UK jurisprudence, particularly in the Court of Appeal’s 2007 decision in Barakat v. Iran. Here, antiquities had been removed from Iran in violation of its export laws and were subsequently held by a London-based dealer. The Court diverged from the precedent established in Ortiz, where cultural heritage laws were treated as public law norms, instead recognizing that Iranian domestic law constituted heritage law and that claims for restitution were consistent with international public policy. The Court further emphasized that States have an obligation under international frameworks to cooperate in preventing the illicit removal of cultural property, including antiquities. Denying recognition of State ownership over such objects would render restitution practically impossible [36] (p. 153).

A comparable approach was evident in the case of the repatriation of the mummified Buddhist monk statue, Zhanggong Zushi, stolen from a Chinese temple in the 1990s and discovered in 2013 in the possession of a Dutch collector. While Dutch courts initially rejected China’s claim, the Chinese judiciary subsequently upheld the restitution request. Although the case did not directly invoke the 1970 UNESCO Convention or the 1995 UNIDROIT Convention, the court applied the principle that, for ownership disputes over cultural property, the applicable law should be that of the State where the theft occurred, rather than where the object was last traded or held [37] (p. 352).

This principle is further illustrated in Greece v. Sotheby’s. A bronze horse statuette first appeared on the art market in 1965 through a Swiss auction house, Münzen und Medaillen AG, and was acquired by the dealer Robin Symes, who later sold it in 1973 to Howard and Saretta Barnet. In 2018, part of the Barnet collection was slated for auction at Sotheby’s New York, and the Greek Ministry of Culture identified the statuette among the items for sale. Greece requested Interpol’s assistance in tracing the provenance, particularly focusing on the original 1967 auction records to establish the date and circumstances of export from Greece. The investigation proved inconclusive due to the passage of fifty years and the destruction of documentation at the Swiss auction house. Nevertheless, Greece pursued restitution from the Barnets’ heirs and Sotheby’s. The U.S. District Court for the Southern District of New York held that claims concerning State cultural property are sovereign, not commercial, and therefore the Court lacked jurisdiction. The Court of Appeals clarified that Sotheby’s could not sue the Greek government, citing the Foreign Sovereign Immunities Act (FSIA), while emphasizing that Greek law establishes State ownership over all antiquities regardless of discovery date or location. This framework effectively situates restitution claims within the exercise of sovereign authority (acta jure imperii). While the decision does not establish lex originis as an absolute rule, it demonstrates that its application can circumvent the constraints posed by the Convention’s non-retroactivity [38].

Despite a growing judicial trend, there remains no express legal norm for cross-border ownership claims stipulating the application of the law of the State of origin. Nonetheless, the principle of lex originis in cultural property disputes was advocated as early as 1991 in the recommendations of the Institute of International Law. At the European Union level, Directive 2014/60 reinforces this approach, establishing that, in inter-Member State relations, the illicit nature of removal and the very definition of cultural property are to be assessed under the law of the claimant State [13] (p. 289). A future amendment to the Convention could explicitly affirm that, in disputes concerning the ownership or illicit removal of cultural property, the applicable law shall, as a general principle, be that of the State of origin (lex originis). Such clarification would strengthen legal certainty and promote consistency with emerging international practice, ensuring that restitution claims are assessed in the light of the cultural and legal context from which the object was removed.

4.3.4. The Ambiguity of Provisions on Good Faith

When a State succeeds in recovering a cultural object, it is required to pay fair compensation to a bona fide purchaser or holder of the object. The concept of “good faith” is a legal notion that varies significantly across different legal systems. Since the Convention does not specify how the holder of a cultural object must demonstrate their good faith, this obligation could be interpreted in a manner whereby a defendant who possesses a valid title is entitled to compensation without having to prove that they acquired the object in good faith. In other words, the holder might receive compensation even if, in reality, they were aware that the object had been exported illegally [13] (p. 235).

To some extent, the 1995 UNIDROIT Convention addresses this issue more clearly in Article 4(4), placing the burden of proof on the holder and providing specific guidance as to the steps that demonstrate due diligence. Although only a limited number of States that have ratified the 1970 UNESCO Convention have also ratified the 1995 UNIDROIT Convention, the latter should serve as a reference point for interpreting the notions of good faith as they appear in the UNESCO Convention [1] (p. 51).

To enhance legal certainty and ensure consistent application, the Convention would benefit from a clearer articulation of the elements constituting good faith. Rather than leaving the concept entirely to domestic interpretation, States Parties could adopt a shared understanding about what good faith in such cultural disputes entails including demonstrable due diligence, inspired by the approach adopted in the 1995 UNIDROIT Convention. The inclusion of indicative criteria would provide a balanced framework that preserves the flexibility of national systems while also reducing the risk that the good faith defence is invoked to legitimize the retention of illicitly exported cultural property.

4.3.5. The Compensation

Under Article 7(b)(ii) of the Convention, if a State successfully recovers a cultural object, it is obliged to pay fair compensation to any bona fide purchaser or holder of the object. However, the scope of such compensation is not clearly defined, nor does the Convention specify whether fair compensation could entail allowing the bona fide purchaser to retain ownership of the cultural object even after its return [13] (p. 235). The absence of specific guidance on how compensation should be calculated may create significant uncertainty for the requesting State, particularly given that source States typically lack sufficient financial resources.

In the case of Beyeler v. Italy, the European Court of Human Rights (ECtHR) found that Italy was required to compensate Beyeler for the financial loss he had incurred. In determining the appropriate compensation, the Court did not consider only factors directly or indirectly related to the value of the painting but reasoned that two additional parameters relating to the conduct of the Italian public authorities should be taken into account. Specifically, in 1954, Italy declared Vincent van Gogh’s Portrait of a Young Peasant to be a work of historical and artistic interest under its domestic law (Law 1089/1936). At that time, the painting was part of the collection of Verusio, a private collector based in Rome. The declaration that the painting was of historical and artistic interest meant that, should Verusio wish to sell it, he was obliged to notify the Italian State, which could then exercise a right of pre-emption to acquire the painting [39].

In 1977, the Swiss collector Beyeler purchased the painting from Verusio for 600 million Italian lire, through an intermediary, Silvestro Pierangeli. That same year, Verusio informed the Italian Ministry of Cultural Heritage of the sale, naming Pierangeli as the contracting party, but concealing that the ultimate purchaser was Beyeler. In 1983, when representatives of the Peggy Guggenheim Collection (PGC) expressed interest in acquiring the painting, Pierangeli disclosed to the Italian Ministry that he had purchased the painting on behalf of Beyeler. Later that year, Pierangeli and Beyeler jointly submitted a declaration to the Ministry stating that PGC intended to purchase the painting for USD 2.1 million. The competent Italian authority, acting cautiously, issued permission for the painting to be transported to Venice for inspection purposes. Assessing the importance of the painting and maintaining serious doubts regarding its ownership, in 1986 the Italian State ordered its transfer to Rome for temporary custody at the Gallery of Modern and Contemporary Art [40].

Due to these delays, PGC’s representatives indicated that they no longer wished to acquire the painting. Meanwhile, in 1988, the Italian State, recognizing the painting’s significance for Italy’s cultural heritage, expressed interest in acquiring it. However, it was willing to offer a limited amount compared to Beyeler’s expectations, who had informed the Ministry that the painting’s sale price amounted to USD 11 million. The Ministry did not respond to Beyeler’s offer, and as a result, Beyeler sold the painting to PGC for USD 8.5 million. Beyeler subsequently informed the Italian Ministry of Culture about the transaction, which responded that the sale did not comply with the requirements of Law 1089/1936, as Beyeler had not held valid title to the painting at the time of the transaction. Moreover, the Ministry explained that it had not exercised its pre-emption right in 1977 because it was unaware of the true identity of the contracting parties [40].

Beyeler challenged the Italian State before the Tribunale Amministrativo Regionale per il Lazio (TAR), seeking annulment of the administrative act authorizing the exercise of the pre-emption right. After his claim was dismissed, he filed an appeal before the Consiglio di Stato and concurrently petitioned the Corte di Cassazione, asserting violations of his property rights and that the compensation awarded was inadequate relative to the loss he suffered. The Corte di Cassazione, considering constitutional questions, referred the matter to the Corte Costituzionale to determine whether the relevant law was compatible with the Italian Constitution. All national courts of Italy ultimately dismissed Beyeler’s claims [39].

Consequently, Beyeler brought the case before the ECtHR under Article 1 of the European Convention on Human Rights, which guarantees the peaceful enjoyment of property. The Court found that a violation of Article 1 had indeed occurred. Nevertheless, it held that the painting must be returned to Italy. For this purpose, the Court awarded compensation of €1,355,000 to Beyeler. In calculating the compensation, the ECtHR considered not only the objective value of the painting but also the low amount initially offered by Italy as compensation for the exercise of the pre-emption right, and the delays in the process of exercising that right [39].

This case illustrates the complexity of determining “fair compensation” in restitution cases involving cultural objects. Although the European Court of Human Rights emphasized the need to consider the conduct of national authorities and the broader public interest, it also revealed how compensation assessments can impose unpredictable financial burdens on the State of origin. Source States, which already bear significant costs and administrative responsibilities in tracing, recovering, and preserving cultural objects, may face an additional and uncertain obligation to pay compensation. The lack of guidance on the criteria or method for calculating such compensation risks deterring these States from pursuing legitimate restitution claims. To safeguard the Convention’s effectiveness and promote a balanced approach, it would be desirable for the Convention to provide indicative criteria for compensation, drawing on the principle of proportionality and taking into account the financial and administrative efforts undertaken by the claimant State.

4.4. Recommendations for Improvement

4.4.1. Enhancing the Provisions Through Amendment

Under Article 25, the Convention may be amended. However, any such amendment would bind only the States that choose to accede to it, and not the States Parties to the 1970 UNESCO Convention itself. Given that the States where the art market is most active have increasingly recognized the importance of protecting the cultural heritage of other nations and have enacted domestic legislation to that effect, a potential amendment presents itself as a practical and promising avenue for strengthening the Convention’s effectiveness. Concurrently, diplomatic engagement in the field of cultural heritage, bilateral agreements within the framework of the 1970 Convention, scholarly publications, a series of restitution and recovery cases, the adoption of codes of ethics, best practices developed by museums and art dealers, as well as the activities and offices of UNESCO and the ICPPR, have collectively shaped a transformed landscape. Within this evolving milieu, the UNIDROIT Convention was concluded, albeit with a number of ratifications that remains significantly lower than that of the 1970 UNESCO Convention [1] (p. 65).

In this context, the prospect of unifying the two Conventions into a single, coherent international legal instrument merits serious consideration. Such an instrument could effectively reconcile the inconsistencies, contradictions, and complexities that currently hinder the objectives these frameworks are designed to achieve. The practical experience gained from the challenges encountered in implementing the 1970 Convention could be systematically integrated into this new instrument. Certain issues could be explored with greater objectivity and analytical rigour, while others could be defined with enhanced precision, thereby reducing the significant disparities and variations that have emerged in domestic implementing legislation. Most States possess cultural heritage that requires safeguarding, intrinsically linked to their traditions, history, identity, and cultural fabric. The manner in which this heritage is protected in a globalized environment is inextricably linked to international cooperation and the observance of legal obligations by other States [1] (p. 65).

4.4.2. Enhancing the Effectiveness of Implementation Through Agreements

Given the considerable challenges associated with amending the Convention, and particularly in light of the reluctance that so-called “market States” might exhibit towards acceding to a text featuring more robust provisions, as well as the potential disruption such amendments could cause to the customary character of its rules, it is imperative to explore alternative mechanisms that could promote more effective implementation [41] (p. 102).

Article 15 of the Convention explicitly empowers States Parties to enter into agreements amongst themselves, which may exceed the minimum protective standards established by the Convention [42] (p. 358–359). Such agreements are intended to complement the Convention, rather than supplant or replace it [1] (p. 56). Within this framework, a number of States endowed with significant cultural heritage have sought to negotiate agreements with Convention States where the art market is particularly active. Illustratively, States such as Bolivia, Bulgaria, Cambodia, China, Cyprus, El Salvador, Greece, Honduras, Italy, Mali, Mexico, and Peru have concluded bilateral trade agreements with the United States for the protection of their cultural property. Furthermore, in pursuit of regulating the transit and concealment of cultural objects, States including Cyprus, Italy, Greece, Colombia, China, Peru, and Mexico have entered into bilateral agreements with Switzerland pursuant to Article 15 [42] (p. 358–359).

Moreover, under Article 9, where a State Party perceives that its cultural heritage is threatened by the illicit excavation of archaeological or ethnological material, it may call upon other States Parties to engage in a coordinated international effort to implement the provisions of the Convention. Within this context, organized initiatives of international pressure, including lobbying by States particularly affected by the illicit trafficking of cultural property, can play a pivotal role in shaping a renewed approach to the implementation of the 1970 UNESCO Convention. A prime example is the coordinated investigative efforts and pressure exerted by Greece and Italy on the Getty Museum to secure the return of cultural objects illicitly removed from their countries of origin and acquired by the institution without clear provenance documentation. This exertion of influence resulted both in the negotiation of bilateral agreements between the museum and the two States and in a broader international awareness among the public and other museums regarding the acquisition of cultural property of questionable provenance [43] (p. 443).

In considering the practical and political feasibility of the proposed improvements, it is essential to situate them within the current international and legal landscape. While the study remains largely analytical, the discussion of amendments under Article 25 and the use of bilateral agreements under Article 15 illustrates avenues that could realistically be pursued by States Parties. Comparative reference to the UNIDROIT Convention demonstrates how international instruments with fewer ratifications can nevertheless influence implementation strategies and provide incremental lessons for harmonization. In this context, potential amendments or bilateral arrangements are evaluated not merely as normative ideals but as measures whose adoption can be facilitated by diplomatic engagement, established best practices, and precedents in restitution cases. By framing the recommendations in this way, the analysis underscores both their normative significance and operational plausibility, offering a grounded perspective that bridges theoretical reasoning with actionable pathways for States Parties.

5. Conclusions

This study offers both theoretical and practical contributions to the field of international cultural heritage law. From a theoretical perspective, it deepens the understanding of the interplay between international legal norms and domestic legal frameworks in safeguarding cultural property, elucidating how fundamental concepts such as good faith, lex originis, and non-retroactivity have been interpreted historically and across different jurisdictions. Through a critical examination of the 1970 UNESCO Convention, alongside national practices and restitution cases, the study identifies enduring conceptual ambiguities and traces their evolution in response to contemporary legal and policy developments.

From a practical standpoint, the research provides evidence-based guidance for States, museums, and other cultural institutions to enhance compliance with the Convention. It informs the development of bilateral and multilateral agreements, the use of digital provenance tools, and strategies to address recurring challenges in restitution and repatriation cases. By connecting doctrinal analysis with empirical findings, the study contributes to more coherent and effective mechanisms for the protection, management, and restitution of cultural heritage.

This article highlights both the achievements and the limitations of the 1970 UNESCO Convention in regulating the protection, restitution, and circulation of cultural property. The Convention established a foundational international framework that recognizes the rights of source States to protect their cultural heritage, prevent illicit trafficking, and recover unlawfully exported objects. It has been effective in promoting cooperation among States and raising awareness of the legal and ethical obligations of museums, collectors, and art dealers.

However, several weaknesses limit its practical effectiveness. First, many provisions are intentionally phrased in broad terms, reflecting a political compromise between the conflicting interests of source and market States, intended to encourage wider ratification. Consequently, this compromise has led to uneven implementation and varying levels of commitment among States Parties. Some countries have adopted strict domestic measures and criminal sanctions, while others rely on bilateral agreements or impose restrictive rules that hinder restitution claims. The absence of effective enforcement mechanisms and sanctions further weakens the Convention, leaving its implementation largely dependent on the goodwill and cooperation of States Parties.

Second, the scope of the Convention is limited. Antiquities from illicit excavations or cultural goods lacking formal registration often fall outside its protection. In this case, establishing provenance is often difficult, and the Convention does not explicitly allow indirect or alternative evidence to support claims. Moreover, its non-retroactive nature excludes objects removed before a State ratified the Convention, leaving important historical losses unaddressed. As previously analyzed, this limitation has, in some cases, been invoked to justify the retention of cultural objects that were unlawfully appropriated in the past by reason of colonialism, political oppression or other reasons. This limitation has often been used, sometimes misleadingly, as an argument to deny the return or argue that before the Convention’s adoption antiquities were removed with no problem. In particular, the current possessor of a cultural object may claim that it was exported before the Convention’s entry into force or before the source State’s ratification, even when the removal was recent, reversing de facto the burden of proof to the possessor’s benefit.

Third, legal notions such as good faith and compensation result in divergent interpretations among States, thereby undermining the Convention’s uniform application. The Convention does not clarify how compensation should be calculated for bona fide purchasers or holders, which can impose unpredictable financial burdens on source States. Similarly, differences in national legal systems and the absence of explicit guidance on the applicable law complicate restitution claims. Cases from Europe, the United States, and Asia demonstrate that applying the law of the State of origin (lex originis) is often the most effective approach, yet this principle is not enshrined in the Convention.

To address these issues, the article recommends several improvements. An effective measure would be to pursue targeted amendments to the Convention, designed to address specific shortcomings. Amendments could clarify definitions, expand the scope of illegality to include unregistered and illicitly excavated objects, and provide indicative criteria for compensation and good faith. Such amendments could be crafted to strengthen the Convention’s effectiveness while ensuring broad acceptance among States, taking into account practical experience, evolving international practices and other foundational texts that have shaped the field, including the UNIDROIT Convention of 1995.

In addition, given the considerable challenges associated with amending the Convention, including the potential reluctance of the so-called “market States” to accede to more robust provisions, it is imperative to explore complementary mechanisms. Bilateral and multilateral agreements have proven particularly effective in this regard, allowing States to secure restitution, regulate acquisitions more consistently, and coordinate protective measures beyond the minimum standards of the Convention. Organized international initiatives, including lobbying and coordinated investigative efforts, have further demonstrated how such agreements can exert practical influence, promote compliance, and raise awareness about the responsible acquisition of cultural property. Digital tools and standardized documentation systems, such as Object ID, can further enhance these mechanisms, facilitating provenance tracking, supporting enforcement, and ensuring that agreements translate into concrete improvements in the protection of cultural heritage.

Overall, while the 1970 UNESCO Convention remains a cornerstone of international cultural heritage law, its effectiveness depends on clearer provisions, consistent implementation, and practical mechanisms to support source States. Strengthening the Convention, whether through targeted amendments or complementary agreements, would better ensure the protection and restitution of cultural property in a fair, clear, consistent, and legally certain manner.