Italy's art police are looking a third ancient statue thought to have gone missing when the Riace bronzes were removed from their watery hiding place.

Italian Culture Minister Francesco Rutelli asked the Protection of Artistic Heritage to investigate the claims of art sleuth Giuseppe Bragho, an expert on the Calabria region where the bronzes appeared in 1972, ANSA said.

Bragho said a diver reported at the time that he saw "three statues, probably made of bronze ... one of them lying on its side with a shield on its left arm."

The two recovered statues are on display at the Reggio Calabria museum.

Bragho said a third statue and other items found by the diver, never made it to the museum and have been sought since. He said he "tracked down and photographed a series of documents which indicate an alarming scenario" but did not reveal what the scenario was.