I was wondering when this sort of thing would happen ... from Taipei Times:

Italian authorities suspect that some Roman antiquities in Japanese museums may have been looted, a news report said yesterday amid efforts by Italy to recover relics of its rich past it says were smuggled out of the country.

The Italian government plans to put together a catalog of about 100 ancient treasures and ask the Japanese Cultural Affairs Agency to cooperate in recovering them, Japan's largest daily Yomiuri Shimbun reported from Rome, citing unnamed Italian prosecutors.

About 50 of the 100 allegedly smuggled items currently reside in the Miho Museum, a private museum in Shiga, western Japan, that is renowned for its collection of antique art, Yomiuri said. The antiquities in question at Miho include a sculpture and fresco painting from ancient Rome.

The report did not say when the suspected items were taken to Japan.

Japanese officials, however, said yesterday they had not been contacted by Italian authorities and had no idea whether any of the Roman artifacts in Japanese museums had been looted.

Suspected

Hiroaki Katayama, the head of Miho's cultural department, said the museum does not know which items are suspected of having been looted, adding that the number of items believed to be from the Roman period is less than 50.

"We believe our collection does not include anything that was dug up illegally. We don't know what kind of proof they have. We would like to know the details [of the allegations] as soon as possible," Katayama said.

Cultural Affairs Agency official Rio Higuchi said officials did not know if any looted antiquities had been smuggled into Japan.

Italy has been cracking down on antiquities trafficking and campaigning to recover artifacts it contends were stolen or illegally exported from the country and sold to European and US museums.

New York's Metropolitan Museum of Art, Boston's Museum of Fine Arts and Los Angeles' J. Paul Getty Museum have agreed to return antiquities.

We've mentioned the Miho Museum before (in passing) ... interesting cast of characters associated with it (e.g. the Maecenas Foundation, the folks behind the Gospel of Judas, that Japanese religious sect we've mentioned before ...)