The Allard Pierson Archaeology Museum in Amsterdam on Wednesday returned a third century B.C. vase to Sicily, saying research into its origins raised doubts about how it left the island, broadcaster NOS reported.
The Centuripe pyxis, a storage vessel decorated with a wedding scene watched by the Greek god Apollo, had been in the museum's collection for nearly 30 years. The return was voluntary.
The museum bought the vase from a Swiss dealer at the Tefaf art fair in Maastricht in 1997. Its provenance documents and export license were missing. The seller claimed it had been in private Swiss ownership before 1970.
That account was undermined in 2016, when Sicilian researchers found a roll of film showing the vase among objects handled by grave robbers in Centuripe, Sicily.
The film also contained a wedding photograph dated 1976, which contradicts the claimed timeline of Swiss ownership.
"Clearly, things did not go by the book," said Rogier Kalkers, who leads provenance research at the museum.
Kalkers said restitution was not legally required because stricter rules introduced in the Netherlands in 2009 do not apply retroactively. "There has been a grey area for museums, collectors, and dealers for forty years," he said.
The museum said it chose to act regardless. "We want to take responsibility and therefore distance ourselves from it," it said.
An Italian delegation attended the handover, including Sicily's heritage minister, Carabinieri officers and a representative of the Italian Embassy.
Kalkers described the return as the start of further cooperation. "This is not a conclusion, but a stepping stone to joint follow-up research," he said.