ATHENS, Greece -- An ancient Greek cup awarded as a prize to the marathon winner in the first modern Olympics of 1896 has been returned to Athens from a German university.

Greece's Culture Ministry said Wednesday that the 6th century B.C. pottery vessel was considered lost for decades until research in 2014 by archaeologist Giorgos Kavvadias identified it in the University of Muenster's collections.

A ministry statement said it was proved "beyond any doubt" that the two-handled wine cup painted with ancient runners was the one given to Spiros Louis, the Greek marathon victor in the 1896.

Following correspondence with Greek officials, the university agreed to return the cup, which was part of a private German collection it had bought in 1986. The statement said the collection had been put together by Werner Peek, a scholar of Greek and historian who lived in Athens during the 1930s. But it was unclear how the cup ended up in Peek's hands.

The vessel was presented at a ceremony at the National Archaeological Museum in Athens, where it will be exhibited for the next three months before being put on permanent display at a museum in Ancient Olympia, birthplace and venue of the ancient Games.

Louis, a humble water carrier with no training in running, won enduring fame in Greece for his unexpected victory on home turf in the marathon, seen as the most Greek of Olympic disciplines. He was presented with a silver cup and a silver medal -- both of which are in Greece -- as well as the drinking cup.