A federal appeals court on Tuesday upheld a lower court ruling revoking the citizenship of a former Nazi concentration camp guard. The U.S. 8th Circuit Court of Appeals ruled that a federal district judge was correct in revoking the citizenship of John Hansl, 81, who lives in Des Moines.

The U.S. Department of Justice filed a complaint against Hansl in July 2003, claiming he hid his military service when he applied for a visa to come to the United States in 1955. He was granted a visa and became a U.S. citizen in 1960.

Hansl was a guard with the Waffen SS at the Sachsenhausen and Natzweiler-Struthof concentration camps in 1943 and 1944. His duties included guarding prisoners from watch towers, marching prisoners at gunpoint to work sites near the prison, court records show.

He was ordered to shoot any prisoner who tried to escape and helped search for an escaped prisoner who was later shot to death, although Hansl did not pull he trigger, court records show.

Hansl claimed he did not voluntarily join the Waffen SS and that officials knew of his military service before he was granted a visa to emigrate to the United States.

The legal argument in the case revolved around a 1953 law designed to control the flow of immigrants to the U.S. after World War II.

Lawyers for Hansl claimed the law required a person to have ''personally assisted'' in the persecution of others before they could be denied a visa.

U.S. District Judge Robert Pratt revoked Hansl's citizenship in April 2005, ruling that Hansl's conduct as a guard left ''no room for factual dispute whether he personally advocated or assisted in persecution.''

On Tuesday, the St. Louis-based court agreed, ruling that the law is clear.

''We need not turn to either the immigration officials' testimony or legislative history to determine the meaning of 'personally assisted' because the language (of the law) is unambiguous,'' the court said.

The court also said that it has previously ruled that duties similar to those Hansl performed as a guard constituted personal assistance in persecution.

''Hansl's service in the Waffen SS as an armed guard at Sachsenhausen and Natzweiler concentration camps constituted personal assistance in the persecution that occurred in those camps,'' the court ruled. ''Because his actions constituted personal assistance in persecution, he was ineligible for a visa -- and the issuance of a visa was improper.

''Accordingly, he was not lawfully admitted to the United States, and his subsequent naturalization was illegally procured.''

The court also rejected Hansl's argument that he was forced to join the Waffen SS as irrelevant.

Hansl was born in Yugoslavia and was drafted into the Waffen SS in 1943, two years after Germany invaded the country. Since his father had small children to raise, the Germans drafted Hansl, court records show.

Hansl's lawyer, Lisa Mattson, of St. Louis, said she was surprised by the ruling because the government had recently turned over evidence that would have shown Hansl was eligible for a visa.

''The policies and criteria used by the state department in 1955 were not considered, which is unfortunate,'' Mattson said. ''We believe those factors were an important and relevant aspect of interpreting the law as it was applied at the time.''

Mattson said she would continue to review the case to determine her next step.

''It's not over and I'm determined to continue to fight vigorously for Mr. Hansl,'' she said.