A reclusive collector who hoarded hundreds of valuable artworks at his Munich home has agreed to cooperate with German authorities' efforts to determine which pieces were seized by the Nazis.

As part of the deal announced Monday, Cornelius Gurlitt will get back those works that are indisputably his.

Authorities found some 1,400 items at Gurlitt's home while investigating a tax case in 2012, though it only became public last November.

Officials say at least 458 works may have been seized from their owners by the Nazis, and Gurlitt's representatives are in talks with several claimants seeking restitution. The works include Henri Matisse's Femme assise, for which two claims have been made.

Officials have said for months they would like to reach an agreement with Gurlitt, who in February filed an appeal against the artworks' seizure.

At least 300-350 works to be returned

The Bavarian Justice Ministry, the federal culture minister's office and Gurlitt's representatives said in a joint statement that works whose Nazi-era history officials are checking will remain in authorities' custody, and the task force set up by authorities to examine them will endeavour to conclude its research within a year. Gurlitt will get at least one representative on the task force.

Works on which background research hasn't been completed in a year will be returned to Gurlitt, but the collector will continue to grant access for further work, the statement added.

Pieces on which restitution claims are pending will be held in trust after the year is up.

All works whose history isn't being examined "will be returned to him promptly," said Gurlitt's lawyer, Christoph Edel.

Gurlitt spokesman Stephan Holzinger said he is expected to get at least 300 to 350 works back. He inherited the collection — which includes works by Pablo Picasso, Marc Chagall and Pierre-Auguste Renoir — from his father Hildebrand Gurlitt, an art dealer who traded in works confiscated by the Nazis.