A task force set up by the German government has determined that just five of 1,500 artworks are Nazi loot from the vast trove discovered in the Munich apartment of late recluse Cornelius Gurlitt.

Gurlitt inherited the massive collection from his father, an art dealer who worked with the Nazis during World War II. 

A report released on Thursday after two years of research stated that four of the five Nazi-looted works were already returned to heirs of their owners. Some 499 artworks were deemed by the researchers as having "questionable history." The looted works were named as: Max Liebermann's Two Riders on a Beach, Henri Matisse's Seated Woman, works by German artists Carl Spitzweg and Adolph Menzel, and one landscape by Camille Pissarro (shown).

Ronald Lauder, president of the World Jewish Congress, called the report's results "meager and not satisfactory."