Marc Chagall. Photo: Wiki Commons.

Previously unregistered works by 20th century masters, including Marc Chagall, Otto Dix, Max Liebermann and Henri Matisse were among the paintings found when German police raided an apartment outside Munich last year, authorities revealed to journalists in a press conference Tuesday.

The total value of the paintings, of which more than 1,400 were discovered, is now estimated at $1.35 billion.

Reinhard Nemetz, head of the prosecutors’ office in Augsburg, said  it was unclear if the apartment’s owner, Cornelius Gurlitt, who apparently inherited the paintings from his father Hildebrant, would face charges.

“We don’t have any strong suspicion of a crime that would justify an arrest,” said Mr Nemetz.

Investigators, he said, had turned up “concrete evidence” that at least some of the works had been seized by the Nazis from their owners or had been deemed “degenerate.”

Gurlitt’s father was tasked with selling art regarded by the Nazis as un-German or “degenerate.”  After World War II he told authorities that all the paintings had been destroyed in the bombing of Dresden.