The British Museum has loaned one of the Elgin Marbles - a headless depiction of the river god Ilissos - for the first time and it will go on display in Russia's St Petersburg's State Hermitage Museum until mid-January.
The relics were acquired by Lord Elgin from the Parthenon temple in Athens between 1801 and 1805, during his time as ambassador to the Ottoman Empire, of which Greece was a part.
The Greeks have repeatedly demanded that the relics be returned to their homeland as they were taken illegally during the country's Turkish occupation. Some even claim that Elgin bribed Turkish officials and effectively stole these sculptures from Athens. The items have remained in the British Museum ever since.
The contested relics shot to prominence once again in October, after lawyer Amal Clooney - wife of Hollywood actor George Clooney - said Greece had a "just cause" on these historical monuments and Britain should feel "embarrassed" for retaining them.
"This is the first time ever that the people of Russia have been able to see this great moment of European art and European thought," MacGregor was quoted as saying by the BBC.