Greece urged Britain to return the Parthenon Sculptures - often called the Elgin Marbles - as one of the world's greatest ancient sites the Acropolis re-opens after the coronavirus shutdown.

The ancient friezes, which include depictions of battles between mythical ancient Greeks and centaurs, were taken by British diplomat Lord Elgin in the early 19th century and are now on display at the British Museum in London.

Britain has always refused to return them, arguing that they were taken with the permission of local Ottoman rulers at the time. Culture Minister Lina Mendoni said in a statement:

"The reopening of the archaeological sites with the Acropolis among them, is an occasion for the international (groups) supporting the return of the Parthenon Marbles to reaffirm their constant demand as well as that of the Greek government for the definitive return of the sculptures to their homeland. It is time for the British Museum to reconsider its stance ahead of the Acropolis Museum’s next birthday, which is on June 20. Does it want to be a museum that meets and will continue to meet modern requirements and speak to the soul of the people, or will it remain a colonial museum which intends to hold treasures of world cultural heritage that do not belong to it?"

The Parthenon Sculptures are a “product of theft” and therefore Greece will “never recognize" ownership and possession by the British Museum, she added, and noted that public opinion in Britain has shown that there is support for the move.

The International Association for the Reunification of the Parthenon Sculptures -- formed in 2005 in Athens and which comprises various national groups - last week sent a letter to the Greek Ministry of Culture proposing a renewed, coordinated campaign to put pressure on the British Museum.

Greece has been campaigning for three decades for their return, arguing that the Ottoman empire was an occupying force and any permission granted during its time is not valid.

Athens has considered suing Britain over the issue but more recently has taken a more diplomatic route, asking the UN's cultural agency UNESCO to mediate - an offer rejected by the British Museum.