Police said in a statement they raided 10 addresses in five states across Germany on Wednesday and were investigating eight suspects aged between 64 and 79 for holding the art works or selling them on.
The coordinated raids were part of a long-term investigation into concealment of stolen goods.
Josef Thorak and Arno Breker made the art works for Hitler's Chancellery, which was designed by his architect Albert Speer and from which he planned to rule a Greater German Reich.
After World War Two, the works were moved to a military barracks north of Berlin before disappearing in 1989.
Hitler's Chancellery was badly damaged in 1945 and its remains were demolished after the war on the orders of the Soviet occupying forces.