After some time, Riewe returned to Germany despite the false rumors that he had been executed. He survived the Soviet labor camp, and was reunited with his family. The Riewe family settled in western Germany, in Hanau, Hesse, where they lived for the rest of their lives. After returning from Russia, Riewe worked for the German Physical Society in various capacity, and he passed away sometime in August 1970, aged 70, according to the manuscript provided by German Physics Society.