The items, which U.S. authorities handed over to Italian counterparts in September, include "The Marble Head of Athena," worth an estimated $3 million, and a fresco stolen from Herculaneum, an ancient Roman city near Pompeii.

Aside from their commercial value, the recovered artworks are of "priceless importance" for Italy's historic, artistic and cultural identity, the head of the Carabinieri police art squad, General Vincenzo Molinese, said in a news conference.

In September, the Manhattan District Attorney's Office had said the antiquities had been sold by convicted looters, and some had ended up in the collection of billionaire hedge fund manager Michael Steinhardt.

Italy has long had a problem with the looting and smuggling of its artistic and archaeological heritage, but the Carabinieri insist they are becoming more effective in tracking down and recovering stolen art.

To showcase their efforts, a so-called Museum of Rescued Art was inaugurated last year in Rome, putting on display dozens of statues, jars, urns, plates and coins in a section of the Baths of Diocletian, once the Roman empire's largest spa.

(Reporting by Cristiano Corvino, writing by Alvise Armellini, editing by Keith Weir)