BERLIN - More than 20,000 art objects seized by the Nazis from Jewish collectors and institutions in France are now searchable online in a database that the creators hope will ease the path for families seeking stolen heirlooms. About half of the listed art works haven't yet been returned to the original owners or their heirs, according to the Conference on Jewish Material Claims Against Germany, which together with the United States Holocaust Museum is the organizer of the project. As an example, a search on Rembrandt revealed that 10 works still hadn't been restituted. The database provides access to the Nazis' detailed records and photographs of the objects plundered in occupied France by the Einsatzstab Reichsleiter Rosenberg (E.R.R.), a task force authorized by Adolf Hitler to loot art across Europe. The E.R.R. set up in France soon after the invasion and sorted its booty at the Jeu de Paume in Paris, from where it shipped the best to Germany and sold less highly esteemed works. 'Families robbed of their prized art works can now search this list to help them locate long-lost treasures,' Julius Berman, the chairman of the Claims Conference, said in an e- mailed statement. 'Organizing Nazi art-looting records is an important step in righting a historical wrong.' The Claims Conference urged museums and dealers to use the database to check their holdings for unreturned looted objects. Users can search for items by artist, owner, inventory number and medium, or they can browse through the 260 collections, mostly belonging to Jewish families. Items range from abstract art to 18th-century furniture, from medieval crucifixes to African masks. Works by Pablo Picasso, Leonardo da Vinci, Vincent van Gogh, Lucas Cranach and Johannes Vermeer are among those seized. 'There is a story, a complex human drama behind all the names in this database,' said Project Director Marc Masurovsky, a consultant to the Holocaust Memorial Museum. 'It can benefit the art world, and also gives insight into the aesthetics and tastes of the time,' he said. 'I hope it will demystify the issue of looting and give as accurate an account as possible of the journey these works took.' 