A handwritten manuscript more than 1,000 years old that was stolen from a Greek monastery in WWI, has been handed back to the Greek Othodox Church.

The Museum of the Bible in Washington said that the manuscript has been transferred to an Eastern Othodox church  in a private ceremony in New York.

Returning the item was in line with the museum's policy, after years of investigating the provenance of it's entire collection.

This was due to early acquisitions by its founders - the owners of the Hobby Lobby craft store chain.

The investigation found to include thousands of items looted from ancient Mesopotamia and Egypt.

Jeffrey Kloha, the Museum of the Bible's chief curatorial officer told the New York Times: "Certainly the marketplace has its challenges.

"Things have been moving in the market for some time, and in some cases decades, that have origins that are not legal."

Next month, the artifact will then be repatriated to the Kosinitza Monastery in northern Greece, where it had been used in liturgical services for hundreds of years before it was stolen by Bulgarian forces in 1917.

Several other American institutions have ended up with artifacts looted from the same monastery, The Greek Orthodox Church noted.

Tess Davis, executive director of the Antiquities Coalition, which aims to combat the illicit trade in antiquities told New York Times: "I think the Museum of the Bible is a great example of how not to build a collection, but I do wish other American museums would follow its example when dealing with their own existing problematic collections.

"In this case, curators saw red flags, they followed where they led, realized the manuscript was stolen, reached out to its rightful owners and voluntarily returned it."

The manuscript was created in the late 10th-early 11th century, The Museum of the Bible's website traces has found.