Cornelius Gurlitt, a reclusive collector whose art collection is worth more than $1.3 billion, said through his lawyer that he will consider claims of restitution for several pieces of his collection that were allegedly looted by the Nazis.

Authorities are currently investigating the collection and detailing which works are legitimately owned by Gurlitt and which are deemed "degenerate" art, the term the Nazi government in Germany used to describe modern art, which it banned, the Associated Press reported. German officials are investigating close to 1,000 paintings, 380 of which are classified as degenerate art, and 590 of which are being investigated to see it they are Nazi-looted art.

In an interview with the A.P., Gurlitt’s lawyer, Hannes Hartung, said his client would investigate restitution claims. Hartung said Gurlitt's colleagues are investigating six of the claims, although the investigation is still in its early stages. Gurlitt previously claimed he would not return any paintings, but Hartung said that will not be the case. Speaking to Der Spiegel in November, Gurlitt said, “I won't speak with them, and I won't voluntarily give back anything, no, no. The public prosecutor has enough that exonerates me.”

Gurlitt inherited the art collection from his father, and authorities recovered 1,500 paintings from Gurlitt’s Munich apartment,  which had been missing for decades. The seized art included lost works from Pablo Picasso, Marc Chagall, Henri Matisse and Paul Klee. Hildebrand Gurlitt, Cornelius’ father, was commissioned by the Nazis to sell art the government designated as “degenerate” art. Instead of selling the art, however, Hildebrand kept it hidden, and Cornelius inherited the paintings after his father’s death.

The German magazine Focus reported the raid on Gurlitt’s apartment, which resulted from a tax evasion investigation. The seizure of the art collection occurred in 2011, but German officials did not acknowledge the raid until after the Focus article was published in 2013, sparking outrage and calls for the release of the full list of paintings.

Although Hartung did not discuss specific details about the art collection or the investigation, the lawyer did state they were discussing the return of an Henri Matisse painting. Previous reports on Gurlitt’s collection said it included a portrait of a woman painted by Matisse that belonged to Paul Rosenberg, who represented Matisse and Picasso. The Matisse painting may belong to Rosenberg’s granddaughter, Anne Sinclair, the ex-wife of former IMF director Dominique Strauss-Kahn.