Over 1,500 paintings previously thought destroyed in World War II have been found in Germany after officials followed up on a hunch. Three years ago, customs officials performed a routine check on a train from Switzerland. On the train was Hildebrandt Gurlitt, a Munich resident who reportedly had a "shifty demeanor." They could never have imagined that the reason for Gurlitt's behavior was an unimaginable "treasure trove" of important artworks.

Gurlitt "was a man who didn't exist," one official told Focus, the German publication that broke the story. He was not registered with the police, tax authorities, or social services — mandatory in Germany — and also held neither a pension nor health insurance. Continuing the investigation, in 2011 officials searched Gurlitt's home, reportedly a squalid budget apartment in the Munich suburbs. Behind "mountains of rotting food and decades-old tin cans" lay a collection of artworks thought to be worth over $1.35 billion, including paintings by Picasso, Matisse, and Renoir.

Much of the collection was seized in Nazi Germany

The collection apparently came from Gurlitt's father, Cornelius, who was an art historian when the Nazis seized power in the '30s. He reportedly acquired hundreds of paintings sold for virtually nothing by Jews attempting to escape Nazi rule, while others are believed to have been seized outright. Many of the works were deemed as "degenerative" by the Nazis and were thought to have been destroyed. They clearly weren't, though, and were instead either found by or given to Hildebrandt Gurlitt, who appears to have made a living by selling low-profile pieces from the extensive collection — anything that wouldn't draw too much attention — investigators also discovered a bank book for an account with over $650,000 in the apartment.

The search is now on for the original owners of the artworks. It's believed that one of the Matisse paintings may belong to Anne Sinclair, the wife of disgraced politician Dominique Strauss-Kahn, the former head of the International Monetary Fund facing trial in France for his part in abetting a sex trafficking ring.