A number of previously unknown works of art by masters are among the trove of Nazi-looted art discovered in a Munich flat.

Bavarian customs officials have now revealed the huge haul includes works by Chagall, Matisse, Max Liebermann and Otto Dix.

They have also denied claims authorities failed to disclose the find for two years.

Art historian, Meike Hoffman, said a lot of the works were believed to have disappeared or to have been destroyed. They’re in relatively good condition, some are dirty but not damaged.

The case, exposed by Focus magazine, poses a legal and moral minefield for authorities.

The Nazi regime systematically plundered hundreds of thousands of artworks from museums and individuals across Europe. It is believed some may have once been on display in German museums, then removed after Hitler’s Third Reich considered them “degenerate”.

With an unknown number of works still missing, museums worldwide are holding investigations into the origins of their exhibits.