A chunk of a stone gutter from the birthplace of the ancient Olympic Games, which was illicitly taken from Greece some 80 years ago, has been voluntarily returned by a German member of the public.

Greece's Culture Ministry said Wednesday that the 75-centimeter (30-inch) long ancient marble fragment was handed over to the Greek embassy in Berlin.

It is now stored at the museum of ancient Olympia, in southern Greece, where the Games were held in antiquity from 776 B.C. to 393 A.D.

A ministry statement said the unnamed German donor believed the chunk may have come from the stadium — where most of the ancient events were held. It didn't say how he acquired it.

Ancient Olympia had an extensive stone drainage network to deal with flooding.