Italy has demanded the restitution of seven antiquities which it believes were looted before being sold by dealers to the Louvre in Paris in the 1980s and 90s, the museum said on Friday.

The claim, first reported in Le Monde newspaper, was made in a letter handed over by Italian Culture Minister Gennaro Sangiuliano in February during a visit to France, a spokesperson for the museum said.

All seven items, which include an amphora as well as ancient Greek vases ranging from the 4th-6th centuries BC, were sold by Italian traders convicted or suspected of trafficking in ancient artworks.

"I consider that works of doubtful provenance are a stain on the collections of the Louvre," the museum's president, Laurence des Cars, told Le Monde. "We should acknowledge and examine that with rigor and lucidity."

An investigation has been launched into the disputed pieces which could lead to their return towards the end of the year.

The Louvre, which is run by the French state, is the world's most visited museum and is home to some of Western civilization's most celebrated cultural heritage.

A former director of the museum in Paris was charged last year with conspiring to hide the origin of archaeological treasures that investigators suspect were smuggled out of Egypt in the chaos of the Arab Spring.

Jean-Luc Martinez, who ran the Paris Louvre from 2013 to 2021, is accused of turning a blind eye to fake certificates of origin for the pieces, a fraud thought to involve several other art experts.