Italy's populist government is to introduce tough new penalties for art and antiquities crime as it vows to crack down on cultural theft as part of its nationalist agenda.

The clampdown on cultural heritage trafficking comes on the heels of several high-profile repatriations of art and antiquities spirited away to London and New York and recovered only after being put up for sale, sometimes for millions.

A wine carafe, a decanter for precious oils, a soup tureen dating back to ancient Greece were among the latest of 16 precious art and archaeological artifacts recovered in the US over the last two years and returned to Italy last week.

Italian government officials say they will soon be ratifying the Nicosia convention, an international agreement establishing penalties for offences such as unlawful excavation, importation and exportation, illegal acquisition and sale of cultural artifacts.

The return of Italian cultural items has been a stated aim of the new populist government made up of the Five Star Movement (5SM) and the League party, who campaigned on an 'Italians first' platform.

“We want to introduce laws on specific crimes so there are stiffer penalties applied to crimes against cultural heritage, which is a fundamental part of our identity,” said the 5SM Culture Minister Alberto Bonisoli in Washington DC at a celebration to return three ancient treasures.