Euphronios Krater
Even with the best of intentions, it may be difficult for museums to completely avoid the acquisition of ill-gotten artifacts. Consider the case of the Euphronios krater. The Metropolitan Museum of Art acquired the 2500-year-old krater — an ornate bowl used to combine water with wine — for $1 million in 1972, thrilled to find one of the few known examples of the ancient painter Euphronios. It had been purchased, however, from Robert Hecht, now on trial in Italy on charges of conspiring to deal in looted antiquities. And while any cloud of suspicion over the krater's provenance was unbeknownst to Met curators in 1972, the museum faced calls from Italy to return the artifact, originally discovered outside Rome.
Current Status: After several years of negotiation, the Met returned the krater to Italy in 2008 in exchange for the rights to display several comparable artifacts on loan.