Germany's Central Office of the State Justice Administrations for the Investigation of National Socialist Crime, officially known as Zentrale Stelle, is directing the investigation in Ludwigsburg, Germany, the German newspaper Der Westen reported.
Chief Prosecutor Kurt Schrimm said the 2011 conviction of John Demjanjuk, 91, for his role in the murders of 28,000 Jews as a guard at the Sobibor camp set a legal precedence for the current investigation. That ruling meant a guard's presence at the site of a mass murder is enough to implicate him as an accessory in the murders.
"The accused was part of the machinery of destruction," the verdict in Demjanjuk's case read.
Schrimm's team is searching for the 50 former guards -- now all old men -- outside of Germany, Der Westen reported Friday. Many former Nazis fled to South America with the help of the Catholic Church, the newspaper said.