It said the website would be regularly updated so people and institutions could tell if they had legitimate claims, but declined to give a time frame for the publication of the other artworks in question. The government also said a task force made up of six experts started working Tuesday on identifying possible former owners.
Looted art was stolen or bought for a pittance from Jewish collectors who were forced to sell under duress during the Third Reich. For the heirs of those collectors, the discovery has raised hopes, while the slow release of information has stirred frustration.
On Tuesday, Jewish groups and art experts welcomed the publication of the 25 paintings, but demanded that the rest be made public quickly.
"It's an important signal that the government intervened after the outrage about the silence surrounding the looted art," said Deidre Berger from the American Jewish Committee in Berlin. "But it's too little, too late. If the government is serious about this, they should get the information up in a way that everybody can access it - people worldwide have a legitimate interest in this."
Prosecutors in the Bavarian city of Augsburg, who are handing the case, acknowledged receiving requests for details from people or institutions with a possible claim to some of the works, but would not say how many.
Lawyer Sabine Rudolph, who represents Glaser's heirs, said that 13 paintings on the website belonged to him before the Nazis came to power. Rudolph said when the Nazis no longer allowed Glaser to work as a lawyer after 1933, he had to sell his art collection to make a living.
"The family, who still lives in Dresden, is very happy about the art found and of course they want them back," Rudolph told The Associated Press, adding that she already had asked Augsburg prosecutors for access to the records.
Among the paintings listed online as formerly belonging to Glaser posted are Otto Griebel's "Child at the Table," a water color featuring a red-cheeked boy with tousled blond hair, and Conrad Felixmueller's "Couple in a Landscape," which shows a man and a woman in front of pine trees and a birch painted in an expressionist style.
Chris Marinello, a lawyer for the family of Paris art dealer Paul Rosenberg, said that he had sent a letter of claim to Augsburg for Henri Matisse's "Woman Sitting in an Armchair" and was "going through the information that has been released" about the newly identified works.
A lawyer for the heirs to late Jewish collector Alfred Flechtheim said that while none of the 25 pieces published online belonged to Flechtheim, he had contacted Augsburg prosecutors and demanded that all the paintings should be exhibited as quickly as possible.
"Two years ago, Cornelius Gurlitt sold a painting that his father bought from Flechtheim in 1934, when he was already on the run from the Nazis," lawyer Markus Stoetzel said. "So we have reason to believe that there may be more Flechtheim paintings in the Gurlitt collection."
Cornelius father Hildebrand Gurlitt was an art dealer who had worked closely with the Nazi regime in the 1930s.
Other paintings posted online included works that had already been showcased at a press conference last week by Augsburg prosecutors, among them an allegorical scene by Marc Chagall and "Horses in a Landscape" by Franz Marc.
- AP