Efraim Zuroff, the top Nazi hunter at the Simon Wiesenthal Center, said there are allegations from a fellow guard that Demjanjuk played "an active part in the mass murder of Jews deported to the Sobibor death camp."
"I very much welcome the decision made by the German authorities to seek the extradition of Demjanjuk and hope that it will be expedited so that he can be prosecuted in Germany and punished for his crimes," Zuroff said.
He noted that Demjanjuk is No. 2 on the center's "most wanted" list of Nazi war criminals — below only the brutal SS doctor Aribert Heim, whose whereabouts are unknown.
"The issue is that he was involved in mass murder; for some of our suspects, we have proof that they were responsible for individual murders, but here we are talking about someone who participated in the process that led to the annihilation of a quarter million Jews" at Sobibor, Zuroff said.