One side to the story that has largely escaped scrutiny, however, is the role of Allied occupation authorities after World War II. After all, they were nominally responsible for ensuring that art looted by the Nazis was returned to its proper owners in the first place. Rightly or wrongly, the state prosecutor in the city of Augsburg has come under criticism for the length of time between the seizure, which was only made public by a German news magazine at the start of this month, and initial attempts to restore the artworks to their legitimate owners. But questions should also be asked as to how Germany's post-war occupiers could have allowed Hildebrand Gurlitt - one of the leading art dealers in the Third Reich - to amass a collection including works by Chagall, Matisse, Picasso, and Dix and then pass that trove on to his son Cornelius.

US soldiers had the tough task of finding the proper owners of looted art. 

Gurlitt Collection: Henri Matisse Seated Woman in an Armchair

"I'm astonished at how quickly the Allied forces in charge of collection points for plundered art were to return it to whoever claimed it," Ori Soltes, an art professor at Georgetown University and a co-founder of the Holocaust Art Restitution Project (HARP), told DW. "There was even a case of art being given to a man claiming to represent Yugoslavia who was in fact just a private collector." 

According to historian Marc J. Masurovsky, another co-founder of HARP, Hildebrand Gurlitt was an established art dealer and a former museum director "who was given significant responsibilities during the 12-year reign of the National Socialists both to recycle thousands of so-called 'degenerate' works purged by decree from German public collections and to acquire untold numbers of works and objects of art at auctions inside the Reich and from galleries, dealers, collectors and artists living and working in German-occupied territories."