German authorities in 2011 uncovered a stunning trove of 1,500 pieces of artwork that had been looted by the Nazis, a German news magazine reported on Sunday.

The masterpieces – valued over a billion euros – were discovered among “mountains of rotten groceries and decades old cans” in a Munich apartment, Focus magazine reported.

While the discovery of paintings by artists such as Matisse, Renoir and Picasso is a victory for the art world, the Commission for Looted Art in Europe sharply criticized the German government’s decision to keep the discovery secret for over two years.

“It really is not acceptable that two-and-a-half years after this art was found, it still has not been published,” Anne Webber, the co-chair of the commission, told The Jerusalem Post.

“We are calling on the German authorities to issue a statement and provide a list immediately and also provide a timetable for its return,” she said.

“Families have been looking for the artwork for 75 years. And it really is 75 years too many.”

The German customs agency did not respond to requests for comment by press time.

During the 1930s and 1940s, the Nazi regime seized thousands of pieces of artwork it considered “degenerate,” and Nazi officials either destroyed or resold the art. Hildebrand Gurlitt, one Nazi art dealer, was tasked by Joseph Goebbels with selling some of the art, according to British and German media reports.

Gurlitt told the authorities that his collection of art was destroyed in the Allied firebombing of Dresden, but the art was apparently passed down to his son, Cornelius Gurlitt.

According to press reports, customs officers became suspicious of the younger Gurlitt in 2010 when he was allegedly found carrying 9,000 euros on a train from Switzerland.

The next year, authorities executed a search warrant on Gurlitt’s apartment and found the artwork.

Gurlitt had allegedly been selling art, piece-by-piece, when he needed money.

But the government’s decision to keep the discovery secret – the artwork has been kept in a warehouse in Munich for examination – drew criticism from Webber.

“Time is running out for families,” Webber said.

A spokesman for Yad Vashem said the museum did not have specific knowledge of the case and is not directly involved in art restitution but said that restitution should “be made as easy as possible.”

“Heirs should have the right to receive back what the Nazis looted, as part of the effort to compensate the Jewish people for the plunder of their property,” Yehudit Shendar, the deputy director of the museums division at Yad Vashem, told the Post in an email.

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