Greek authorities are continuing to press museums and galleries around the world for the return of ancient treasures.

The Louvre in Paris has been asked to refrain from displaying a statue of Apollo on loan to the museum from a US institution.

Greece claims that the disputed statue, attributed to the sculptor Praxiteles, was illegally obtained by the Cleveland Museum in Ohio, AFP reports.

Meanwhile, a leading Greek cleric has requested the return of a fifth century piece of the Parthenon from the Vatican collection. Orthodox archbishop of Athens and of all Greece, Christodoulos, asked Pope Benedict to hand back the fragment of the ancient temple.

According to Reuters, the request, made during the signing of a joint declaration of common interest by the pope and the most powerful Greek cleric, confused the pope who seemed unaware of the existence of the piece of the Parthenon in the vast Vatican museums collection.

Greece has been battling for the return of its ancient treasures, which have found their way into collections around the world, particularly the Parthenon marble friezes and decorations. A museum has already been built in Athens to house pieces of the Acropolis monument, including the Elgin Marbles currently held by the British Museum.

The issue of ancient works of art and cultural artefacts held in countries other than their nation of origin has become a more and more important one in the world of museums and galleries in recent years, with many governments calling for the return of their heritage from overseas.