A register of around 20,000 artworks looted by the Nazis in World War II from Jewish families has been put online in the hopes of reuniting the paintings and objects with their rightful owners.

The project, which started in 2005, is a joint initiative by an organisation called Claims Conference and the US Holocaust Memorial Museum.

"Decades after the greatest mass theft in history, families robbed of their prized artworks can now search this list to help them locate long-lost treasures," said Julius Berman, Claims Conference's chairman.

The website www.errproject.org/jeudepaume was created using the archives of the German agency tasked with cataloguing the plundered art works from 1940 to 1944 - the Einsatzstab Reichsleiter Rosenberg.

Those dossiers are today housed in the archives of the French foreign ministry, the US national archives and the German federal archives, historian Marc Mazurovsky told AFP.

Most of the artworks belonged to French or Belgian families and were gathered up and added to an inventory by the Nazis at the Jeu de Paume Museum in Paris, during the German occupation of France.

"It is now the responsibility of museums, art dealers and auction houses to check their holdings against these records to determine whether they might be in possession of art stolen from Holocaust victims," said Mr Berman.

The website lists the works and a description - mostly in German, but sometimes in French - and in many cases the names of the owners that they were taken from.

"The database brings together the scattered records. For the first time it's all searchable, with photographs, details, etc," said Wesley Fisher from the Claims Conference.

"For the first time it looks at everything that was looted and from whom it was looted. In terms of the ability of claiming, it's great."

A total of 260 collections and 269 owners have been identified in the database.

- Reuters