"At the moment we are negotiating with six claimants over about three percent of the collection," said lawyer Hannes Hartung in a statement on Gurlitt's newly-launched website. "Nobody else has come forward to date."
The 81-year-old Gurlitt launched the website on Sunday to defend himself.
"I just wanted to live with my pictures in peace and quiet," he wrote in a signed open letter on the site's home page. "Much that has been written about me and my pictures is not true or is incorrect."
Among Gurlitt's collection is believed to be a number of pieces of "looted" art taken forcibly from Nazi victims.
Other works in the 1,400-strong collection were legitimately bought by Gurlitt's father Hildebrandt from the Nazis, Hartung added.
Hildebrandt worked as an art dealer for the Third Reich and his son inherited the paintings.
Gurlitt’s lawyer said the works, which were considered "degenerate" by the regime, were taken down from German museums in 1937 and bought by Hildebrandt.
Hundreds of pictures and paintings were removed from Gurlitt’s Munich apartment in 2012 by prosecutors. But news of the trove only broke late last year in German magazine Focus. The provenance of hundreds of the works is now being investigated by authorities.
But lawyers for the 81-year-old collector claim he has been unfairly treated by authorities, who confiscated the paintings during a routine search of his flat.
"In Germany there are many public and private collections in which the share of potential looted art is much higher than in the Gurlitt collection – yet there are clearly no sanctions [imposed against] the collections or the museum directors responsible," added Hartung.
Controversy over the true ownership of some of the long-lost treasures has raged since the collection's existence was leaked to the media last autumn.
Gurlitt's legal representatives launched the website in German and English including legal briefings, links and information about the works to "de-emotionalize" the debate.
They are hoping to put the legal case for the collector to keep the vast majority of his paintings – but say they remain open to discussion.
"With this information page we want to make clear again that we are open to dialogue with the public as well as any claimant," said Gurlitt's spokesman Stephan Holzinger in the statement. Claimants can now come forward using the site's online form, he added.