Baur was arrested by the Gestapo in 1942. Baur had been previously cast in a German production, Symphonie eines Lebens, that was shot in Berlin, and that German officials, especially Joseph Goebbels, wanted to showcase as an embodiment of the collaboration between occupied France and Nazi Germany. When a false report mentioned that Baur was Jewish, the same officials felt duped, and the Gestapo tortured Baur for four months. He was then cleared of the accusation and released, but never recovered from his ordeal and died a few months later.
Academy Award-winning American actor Rod Steiger cited Baur as one of his favorite actors who had exerted a major influence on his craft and career.