Washington - A former Nazi concentration camp guard who concealed his role in the Holocaust has been stripped of his American citizenship and barred from the United States, the Justice Department said Thursday.

Romanian-born Martin Hartmann, 88, joined the Nazi SS Death's Head Guard Battalion at the Sachsenhausen camp near Berlin in July 1943 and served with the Nazis until World War II ended in May 1945.

He withheld his Nazi past when he immigrated to the U.S. in 1955 and when he later applied for U.S. citizenship, according to a complaint in federal court in Washington. Both times, had he disclosed his service with the Nazis, he would have been disqualified.