European Council Directive 93/7/EEC creates a regime for the return of cultural property within the Community for cultural objects belonging to the national artistic, historical, or archaeological heritage which has been illegally exported from a member state.
Martin Bailey of the Art Newspaper has an example of this in practice. Two works by Francesco Guardi have been seized by Scotland yard in London. The paintings, The Departure of the Bucintoro to San Nicolo on the Lido and The Return of the Bucintoro to the Palaxxo Ducale (picture here) were owned by Lord Shuttleworth, and were later bought by an Italian, Mario Crespi in 1952. The paintings were purchased three years ago by an Italian art dealer, but it appears an export licence was made in Milan but the works were perhaps intentionally misattributed to an “anonymous artist” thereby allowing for their export. When a UK art dealer sought to re-export the works from the UK, he correctly labeled the works. The works may be worth “€6m ($9.4m) in Italy, but over £10m ($20m)” elsewhere.