The drinking vessel known as a "Skyphos" had been presented to Greek runner Spiridon Louis in recognition of victory in the marathon at the first Olympic Games of the modern era in Athens.

The vessel dates back to the 6th century BC and was presented by archaeologist Ioannis Lambros, who described it as "a most appropriate prize to the winner who will be worthy of so much glory".

"Antiquity seems in this way to contribute to celebrating the victory of the winner of the marathon race."

It remains a mystery how it became part of the collection assembled by  controversial Nazi archeologist Werner Peek, who worked at Greek archaeological sites in the 1930s.

Many suspect it may have then been given to Nazi leader Hermann Göring, who is thought to have have smuggled the piece back to Germany.

Many years later, Peek sold his collection of some 70 artefacts to the University of Munster in Germany.

The true significance of the skyphos only came to light recently, after Dr Georgios Kavvadias, a vase specialist, spotted a photo in a book and requested the return of the original to Greece.

The return to Athens was marked by a special ceremony at the National Archaeological Museum.

"This is a wonderful gift to the Greek people," Greek Culture Minister Lina Mendoni said.

"An ancient Greek vase whose meaning lies not so much in that it is a work of antiquity, nor in its artistic value, although it is of great importance, but in that it is at the same time linked to a singular event and an important figure in modern Greek history."

Maria Lagogiannis, director of the Greek National Archaeological Museum, spoke at a gathering including Hellenic Olympic Committee President Spyros Capralos, Greek Government officials and representatives of Munster University.

"Today, the return of the ancient skyphos from the Münster University Collection shows where dialogue and mutual respect among peoples can lead. 

"Culture creates bridges that connect our peoples."

Dr Achim Lichtenberger, her counterpart at the University of Munster said: "The skyphos has a highly symbolic significance for Greece, the birthplace of the Olympic Games - we naturally wanted to give it back."

It is hoped that a replica of the vessel will be made for presentation to the University of Munster.

The original will go on display at the museum in Ancient Olympia when the Tokyo 2020 flame is kindled next March.