"We are in a position to help where courts have been unable to, owing to jurisdictional limitations," said panel head Jutta Limbach, a former German supreme court justice.
The panel will solicit requests via a German government-funded website that lists thousands of works of art and books seized by the Nazis or Soviets and still missing six decades later.
The site is run by a team of German investigators based in the eastern city of Magdeburg.
From their records of 3.5 million books, documents and works of art, they have compiled the "Lost Art" Internet database (http://www.lostart.de), comprising 46,000 treasures that can be described in detail and could plausibly show up at art sales.
Most belonged to 300 museums, libraries and archives that either shifted their collections to rural warehouses during the Second World War or were visited by Soviet military trophy teams after the War.
Some of the art was snatched by ordinary looters, both civilians and soldiers taking advantage of the end-of-war breakdown of order. Since 2001, items seized from private Jewish collections by the Nazis have also been listed.
The team was set up in 1998 to coordinate a needle-in-a-haystack search that takes in everything from upscale New York salerooms to dusty storerooms of Central Asian libraries where some of the items may have survived.
The website, which was launched in April 2000, has had more than 10 million visits so far.
Initially the coordination team was only to help public institutions that are trying to recover their pre-war collections.
Then its role was widened to helping private owners, especially the Jewish collectors whose treasures were confiscated from 1935 on. Private individuals who fled their homes at the end of the war can also report art losses.
The idea is that when an art dealer or museum receives an item of murky provenance, they can do a quick Internet check to see if there is a posting about it. Anybody can post a "missing" notice.
The team has been disappointed that word has not spread about the database, which is accessible in German, English and Russian.
Two years ago a painting was offered for sale to the Jewish Museum in Berlin: the museum duly asked for a check, and it was discovered the item had been seized by Soviet forces from a museum in the eastern German city of Goerlitz at the end of the war.
The team cannot force people to return stolen art, but it can bring the facts out in the open so the parties can decide.
Most of the private postings have a connection to the sufferings of an individual German Jew, and each of their stories casts its long shadow into the Germany of today. Internet: http://www.lostart.de