Nazi hunting is the investigation and pursuit of former Nazi officials and SS after the end of World War II. This involves tracking down and gathering information on such individuals, typically for use at trial on charges of war crimes and crimes against humanity during the Holocaust. Nazi hunters were active around the world for decades after the fall of the Third Reich, when many key Nazi figures escaped military trial by fleeing to South America and elsewhere. Prominent Nazi hunters include Simon Wiesenthal, Tuviah Friedman, Serge Klarsfeld, Beate Klarsfeld, Ian Sayer, Yaron Svoray, Elliot Welles, and Efraim Zuroff. Nazi hunting may overlap with the pursuit of Nazi collaborators.