That’s a lot of loot!

Authorities have recovered about 1,500 modernist masterpieces – worth an eye-popping $1.3 billion – that were believed to be looted by the Nazis.

The paintings, including works by Picasso, Matisse and Chagall, were discovered in the Munich home of an 80-year-old man, the German news weekly Focus reported.

The works were either swiped outright from Jewish collectors or confiscated as “degenerate art” during the 1930s and 1940s.

They then somehow wound up in the hands of German collector Hildebrand Gurlitt, whose son Cornelius inherited them when the old man died.

Gurlitt aroused suspicion in 2010 during a routine police check while on a train from Siwtzerland to Munich.

Cops raided his squalid apartment a year later and found the paintings hidden in a room where the reclusive Gurlitt had also left plates of rotten food and other garbage.

They have since been stored in a safe house outside Munich, where officials are expecting a large number of people to come forward claiming the artworks belonged to them or their families.

“The paintings were categorized as ‘degenerate art’ by the Nazis, who either confiscated them or stole them from Jewish art collectors,” the magazine said. “The customs raid to retrieve them was a clandestine operation and kept secret by the authorities.”

One of the Matisse paintings once belonged to French art dealer Paul Rosenberg, whose granddaughter Anne Sinclair was married to French horndog Dominique Strauss-Kahn.