Fritz Klein was born in Feketehalom, Austria-Hungary (now Codlea in central Romania). Klein was considered a Volksdeutscher, or ethnic German. He studied medicine at the University of Budapest and completed his military service in Romania, finishing his studies in Budapest after World War I. He lived as a doctor in Siebenbürgen (Transylvania). In 1939 as a Romanian citizen he was drafted into the Romanian army, where after the outbreak of the war with the Soviet Union in 1941 he served as paramedic on the eastern front. In May 1943 Romanian dictator Marshal Antonescu, on a demand from Hitler to release ethnic Germans in the Romanian Army, drafted them into the German army. Hence Klein became a soldier in the Waffen-SS, was listed in the SS-Personalhauptamt, and was posted to Yugoslavia. On 15 December 1943, Fritz Klein arrived in Auschwitz concentration camp, where at first he served as a camp doctor in the women’s camp in Birkenau. Subsequently, he worked as a camp doctor in the Gypsy camp. He also participated in numerous selections (“Selektionen”) on the ramp. In December 1944 he was transferred to Neuengamme concentration camp, from where he was sent to Bergen-Belsen concentration camp in January 1945. He remained at the camp with commandant Josef Kramer and assisted in handing it over to British troops. Klein was imprisoned and required to help bury all unburied corpses in mass graves. The British Fifth Army Film & Photographic Unit photographed Klein standing in a mass grave in a well-known 1945 photo. Fritz Klein and 44 other camp staff were tried in the Belsen Trial by a British military court at Lüneburg. The trial lasted several weeks from September to November 1945. During the trial Anita Lasker testified that he took part in selections for the gas chamber. He was sentenced to death and hanged at Hamelin jail by Albert Pierrepoint on 13 December 1945.