After Germany's defeat in World War II, many Nazis who were sought by the Allies as suspected war criminals fled to Brazil and hid among the German-Brazilian communities. The most famous case was Josef Mengele, a doctor who became known as the "Angel of Death" at the Auschwitz concentration camp. Mengele performed medical experiments with living humans, always without anaesthesia, for the purpose of researching the perfection of the Aryan race.