OTTAWA -- The federal government is trying to strip an 83-year-old Ontario man with an alleged Nazi past of his Canadian citizenship and kick him out of the country a half a century after he emigrated here.

Ottawa is seeking to deport Jura Skomatchuk, of St. Catharines, Ont., in the 21st war crimes case of its kind in Canada since 1995.

Mr. Skomatchuk is accused in documents filed in the Federal Court of Canada of being a member of a Nazi concentration camp guard group involved in 200 anti-Jewish operations, including mass shootings and the notorious "harvest festival" massacre resulting in the execution of 40,000 Jewish inmates in three camps.

He could not be reached for comment yesterday but has already publicly denied the allegations to the media, saying he was never in the Nazi camps.

Government officials would not comment on the specifics of Mr. Skomatchuk's case but said anyone who enters Canada with an accusation of war crimes will be "rooted" out of the country.

"Canada will not be a safe haven for people against whom there are allegations they participated in war crimes against humanity, genocide or other similar atrocities anywhere in the world at any time," said Terry Beitner, director and general counsel of the Department of Justice's War Crimes Unit in Ottawa.

"I can't comment on the case specifics because the case is before the court," said Maria Iadinardi, a spokeswoman for Citizenship and Immigration Canada. However, she added: "We take these kinds of cases very seriously."

The federal government charges in court documents that Mr. Skomatchuk used false documents or fraud to obtain his Canadian citizenship and knowingly concealed important details about his past -- including his alleged membership in the Nazi concentration camp system.

It is alleged that Mr. Skomatchuk -- who emigrated to Canada from Britain in 1952 -- was a guard in labour and concentration camps in Nazi-occupied Poland, Germany, and Austria during the Second World War. Canada came under international scrutiny in 1997 over accusations that it was complacent in pursuing alleged Nazi war criminals who emigrated after the war.

The story -- which aired on 60 Minutes in 1997 -- broke when Steve Rambam, a Brooklyn based detective, said he found 150 ex-Nazis living in Canada.

Mr. Rambam has continued to be critical of the Canadian government for not acting fast enough to remove war criminals. "The Canadians are scum," he told the Chicago Tribune earlier this year.

Mr. Skomatchuk's case is the 21st in Canada involving allegations of war crimes during the Second World War. Of those, the federal government has won eight cases and lost three. The remaining 10 are still winding through the courts while some of the alleged war criminals have already died, Mr. Beitner said. Another case is expected to be launched soon, but he would not disclose further details.

"We have a diminishing number of the files because of the age of the cases, but it's very important work and there's a clear principle and a message that we're going to send out," he said.

The government is also focusing on allegations against more recent arrivals, from places such as Rwanda and the former Yugoslavia.

[UPDATED AT 6:10 PM EST Saturday, Mar. 06, 2004]