Story highlights John Kalymon was a member of a Nazi-backed police unit, a court has found

He came to the United States from Germany in 1949 and became a U.S. citizen in 1955

Efforts continue to find the few former Nazis remaining in the United States

A 90-year-old Michigan man who officials say rounded up and shot Jews in Nazi death camps during World War II is a step closer to being deported, the Justice Department announced Tuesday.

In January, a judge found John Kalymon of Troy, Michigan, to have been an armed member of the Nazi-sponsored Ukrainian Auxiliary Police from 1941 to 1944.

Tuesday, an appeals board dismissed Kalymon's attempt to block his deportation from the United States. Kalymon immigrated to America from Germany in 1949 and became a U.S. citizen in 1955. A federal judge in Detroit revoked his U.S. citizenship in 2007.

"John Kalymon and his Ukrainian Police accomplices were indispensable participants in Nazi Germany's campaign to exterminate the Jews of Europe during World War II," said Assistant Attorney General Lanny Breuer. Breuer said tens of thousands of Jewish men, women and children were murdered in L'viv or rounded up and shipped to the Nazi death camp in Belzec or to Nazi forced labor camps.

In a news release last month, the Justice Department said Kalymon "personally shot Jews while serving, killing at least one" and "participated in violent anti-Jewish operations in which Jews were forcibly deported to be murdered in gas chambers and to serve as slave laborers."

"This case is one of more than a hundred cases successfully prosecuted by the Department of Justice against wartime Nazi perpetrators," said Eli Rosenbaum, head of the Justice Department's Nazi-hunting unit.

Rosenbaum said that since the government launched its program to find and deport former Nazis in 1979, 107 individuals have been prosecuted, and 180 suspected Axis persecutors who attempted to enter the United States have been blocked from doing so.

Although authorities believe only a small number of former Nazis -- mostly in their 90s -- remain alive in the United States, the government is determined to keep up the hunt and deport those they find.

Rosenbaum said the program "reflects the government's continuing commitment to pursuing justice on behalf of the victims of the Holocaust and other human rights crimes."