In a release sent Friday, the center alleges Karkoc was a Ukrainian SS commandant who hid his wartime record to enter the United States after World War II.
Karkoc was allegedly an officer in the SS Galician Division, which was responsible for committing atrocities against civilians, the release said.
Rabbi Marvin Hier, founder and dean of the Wiesenthal Center, asked Eli Rosenbaum, director of strategy and policy in the Human Rights and Special Prosecution Section of the Department of Justice, to immediately investigate Karkoc.
"In view of the serious charges leveled against Michael Karkoc, namely that he was the commander of an SS-sponsored military unit involved in atrocities against men, women and children and that he lied about it to American authorities in 1949 to gain entry into the United States," Hier said in a letter to Rosenbaum.
"As you very well know, some of the worst atrocities were committed in Eastern Europe by local Nazi collaborators," he added. "The fact that Karkoc was, in addition, a member of the Galician SS should, in itself, be sufficient reason to begin an investigation. That he is 94 years old should have no bearing on the fact that he has never answered for the crimes he is suspected of committing."