LA HABRA, Calif. (AP) _ The Justice Department has begun deportation proceedings against a retired clerk who allegedly supervised slave laborers at two Nazi concentration camps and lied about his past to enter the United States.

The Office of Special Investigations, the division charged with ferreting out war criminals who entered the United States, filed a show-cause order Monday in Immigration Court in Los Angeles against Bruno Karl Blach, 65, of La Habra.

The government alleged in the order that Blach, an ethnic German born in Czechoslovakia, served as a dog handler and supervised slave laborers at the Dachau concentration camp from 1940 to 1943 and then at the Wiener-Neudorf camp from 1943 to 1945. It also alleges he took part in the forced march of prisoners from Wiener-Neudorf to the Mauthausen camp in 1945.

At the camps, those prisoners, including Jews, Gypsies, homosexuals, political dissidents and others deemed unworthy by the Nazis, were either killed outright or lived as slave workers under the constant threat of starvation, disease and brutality.

Blach admitted serving as a concentration camp guard, but denied any criminal actions.

''I didn't do anything wrong at all,'' Blach said. ''I didn't have any contact (with prisoners) at all.''

Blach said his job at the camps was ''the lowest grade you can have in the Army.''

''When you are drafted, what do you do? I didn't have any choice. I had to do what they told me,'' he said.

The Justice Department, however, says that Blach voluntarily joined the Nazi Party and, in June 1940, the Waffen-SS, the combat arm of the Nazi secret police.

The show-cause order also contends that Blach illegally immigrated in March 1956 by concealing his Nazi past - immigration fraud punishable by deportation.

Blach, who retired from clerking at a grocery store distribution center, said Justice Department investigators had twice interviewed him in recent years, but he was unconcerned because ''I have not done anything wrong.''

No hearing date has been set.

Blach's case is one of about 35 similar cases pending in the court this year, said Neal Sher, director of the Office of Special Investigations.