Heirs of a German Jewish art dealer filed a complaint against Bavaria on Monday in the U.S. District Court in Manhattan.

Michael Hulton, a San Francisco doctor, and his stepmother Penny Helton, of Hertfordshire, England, claim that eight paintings owned by Alfred Flechtheim - before he fled the Nazis in 1933 - should belong to them. They are heirs to Flechtheim's nephew and heir Henry Hulton.

The complaint was filed against Bavaria and the Bayerische Staatsgemaldesammlungen (Bavarian State Paintings Collections), and states that several works owned by Flechtheim are displayed at venues such as Munich's Pinakothek der Moderne museum. The Hultons contend that Flechtheim's collection included Max Beckmann's "Duchess of Malvedi" (1926), "Still Life with Cigar Box" (1926), "Quappi in Blue" (1926), "Dream—Chinese Fireworks" (1927), "Champagne Still Life" (1929) and "Still Life with Studio Window" (1931); Juan Gris' "Cruche et Verre Sur un Table" (1916) and Paul Klee's "Grenzen des Verstandes" (1927).

The artwork may have been handled by notorious art dealer Hildebrand Gurlitt who collaborated with the Nazis. (Some 1,500 artworks were found in Gurlitt's son's Munich apartment in 2012.)

"The paintings would have remained accessible to Flechtheim but for the climate at the time," the Hultons' lawyer, Nicholas O'Donnell, said in an interview. "The state-level program of Aryanizing Jewish businesses made the confiscation possible."

Flechtheim died impoverished in London in 1937. His wife committed suicide in 1941.