Such a move "would open a Pandora's Box and cause an avalanche of trials" by rival presumed heirs of the stolen art, Ronal Lauder, the head of the World Jewish Congress, told the German weekly Der Spiegel.
In the same interview, German Culture Minister Monika Gruetters said the government was in talks with Bern's Museum of Fine Arts over the 1,280 paintings, drawings and sketches by Picasso, Monet, Chagall and other grand masters.
The works were seized in early 2012 when they were discovered by chance during a tax evasion probe, and Gurlitt willed them to the museum.
"I am sure we will reach a good and reasonable solution," Gruetters said in the interview to be published tomorrow.