MUNICH — Hundreds of works of art by Picasso, Matisse and other masters of the 20th century — seized by the Nazis, lost for decades and now worth more than $1 billion — were reportedly found among piles of rotting groceries in a German apartment.
The find would be among the largest in the worldwide effort, underway since the end of World War II, to recover masterpieces plundered by the Nazis from Jews inside Germany and from elsewhere in Europe, considered the largest art heist in history.
Experts will appraise the works — paintings, drawings and prints — but the German news magazine Focus, which broke the story, put the value at more than 1 billion euros, or $1.3 billion.
German authorities have not released photos of the cache, which also includes works by Marc Chagall and Paul Klee. Investigators found it two years ago, after a man taking the train from Zurich to Munich was found carrying a large but legal amount of cash.
The man was the son of Hildebrand Gurlitt, who was a modern art specialist in the early 20th century. Joseph Goebbels, the Nazi propaganda minister, recruited Gurlitt to raise cash for the Third Reich by selling art that had been deemed degenerate by Adolf Hitler.
When Hildebrand Gurlitt died, in a traffic accident in 1956, his son inherited the art, apparently unaware of its origin.
Focus reported that the son, Cornelius Gurlitt, 80, kept the works hidden in darkened rooms in his disheveled, food-littered apartment in Munich. He sold a painting now and then when he needed cash, the magazine said.
Much of the work was already known from reproductions, said Walter Grasskamp, a professor at the Academy of Fine Arts in Munich.
“I think the surprise will be bigger in terms of politics: Who owned it, how was it taken away, was it legal — obviously not,” Grasskamp said. “What about the original owners, where did they end? I think this is a question as interesting as the value for the art market.”
It was not clear why German authorities kept the find secret for two years. The British newspaper The Guardian reported that it may be because of diplomatic and legal complications, particularly claims for restitution from around the world.
International warrants were out for at least 200 of the prized works, according to Focus. The magazine reported that the recovered collection is being stored in a secure warehouse in Munich for now.
Asked about the Focus report, a spokesman for the German government, Steffen Seibert, said that authorities were aware of the case and supplying “advice from experts in the field of so-called degenerate art.”
More than 20 percent of the art of Europe was looted by the Nazis under Hitler, and as many as 100,000 works are still thought to be missing, according to the U.S. National Archives.
The allies recovered and cataloged much of the art, which had been stashed by the Germans in churches and other buildings. Gen. Dwight Eisenhower personally inspected some of the stolen treasures after the allied victory.
Grasskamp, the professor, said that the discovery should be deemed not a great find for Germany but a reminder of its dark past.
“It is connected with the worst chapter of German history, so it’s not a triumph, it’s not the ‘Nazi treasure,’ which is rubbish,” he said. “I think this is an interesting peeping hole into a dark story.”
Erin McClam reported from New York. Reuters and The Associated Press contributed to this report.