Approximately 1,500 paintings looted by the Nazis during World War II were found in a Munich apartment, the German newsmagazine Focus reported Sunday.

The hoard of classical modernist works included pieces by Pablo Picasso, Henri Matisse, Marc Chagall, Paul Klee, and Max Liebermann. They are worth an estimated $1.38 billion (NIS 4.87 billion).

The Nazis confiscated works they considered degenerate, by modernists or Jewish artists. They also took thousands of paintings from Jewish collectors.

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This collection was found during the spring of 2011, when German authorities investigated Cornelius Gurlitt, an 80-year-old recluse, for tax evasion. Gurlitt’s father, Hildebrand, had been an art dealer in Munich in the 1930s and 1940s, and bought and sold degenerate art during the Third Reich. Cornelius had been living off the income from paintings he occasionally sold.

When German officials searched Gurlitt’s apartment, they found the valuable cache. The find had been kept secret until now.

Two hundred of the pieces had warrants out for them.

Last month, a major investigation into whether art hanging in Dutch museums may have once been Nazi loot yielded an unexpectedly large result — 139 suspect works, by masters such as Matisse, Klee, Kandinsky and others.

Experts say between 250,000 and 600,000 pieces of art looted by the Nazis were never claimed and remain in the possession of museums, governments and private collectors worldwide.