German tax inspectors found 1,500 modernist masterpieces in a squalid Munich apartment, including works from Pablo Picasso, Henri Matisse, Marc Chagall, and Paul Klee.
The artwork was stolen by Nazis or bought for almost nothing from Jewish owners during World War II.
Inspectors were investigating 80-year-old Cornelius Gurlitt, the reclusive son of an art dealer Hildebrandt Gurlitt, who had helped Nazis collect what they called “degenerate art.”
At least 300 of the paintings are thought to belong to a body of 16,000 pieces deem “degenerate art” and taken by Nazi authorities.
Hildebrandt Gurlitt, who died in 1956, claimed the art was destroyed during the 1945 fire-bombing of Dresden, but his elderly son has been hoarding it among cans of expired food and juice boxes for at least 50 years.
Authorities say the stash is worth at least $1.35 billion. Guritt would occasionally sell one of the paintings if he was need of money.
Since the discovery art historian Meike Hoffmann, of Berlin University, has been studying the origin and value of the work.
Gurlitt’s Schwabing apartment was first searched in spring 2011, but German customs didn’t make the find public because they expect to receive a large number claims from descendants of the former owners from all over the world, according to the Guardian.