A 15-year battle by the federal government to bring alleged Nazi war criminals to justice was dealt a serious blow yesterday as a Federal Court of Canada judge threw out an attempt to denaturalize a man accused of helping execute dozens of Ukrainian civilians.

Judge Marc Noel said that not only did the government lack proof that Johann Dueck was a war criminal, but it also couldn't even show he was a member of a collaborating police force in the Ukrainian town of Selidovka.

Judge Noel said that even had Mr. Dueck been a German collaborator when he immigrated to Canada in 1948, immigration officials had no legal authority to screen and exclude collaborators.

Defence lawyers Donald Bayne and Peter Doody said the latter finding seriously endangers any of the dozen remaining denaturalization cases that date back to the same period.

The lawyers were also highly critical of the government for subjecting Mr. Dueck to years of emotional and financial devastation based on 55-year-old hearsay and flimsy conjecture.

"There was vilification of this man for the past 4½ years," Mr. Bayne said.  "Then, they stand up at the beginning of the trial and have the nerve to say they have no evidence of war crimes.

"It has broken his family financially, and imagine all the emotional hardship of thinking about being sent back this way to a country you have not seen in many years."

Mr. Bayne and Mr. Doody said the government should be called to account for a war crimes venture that has resulted in virtually no successful prosecutions or denaturalizations, at the expense of numerous ruined lives.

Several years ago, the federal government fell back on denaturalization proceedings as its central war crimes strategy after several failed attempts to prosecute suspected war criminals in Canada.

Two men have been deported, while another two left voluntarily.  Another 15 cases are pending.

"If they are running cases that have no war crime component to them as part of ostensible war crimes strategy, Canadians have to ask why are they committing another $46-million to them?"  Mr. Bayne said in reference to a financial commitment to the war crimes unit last July by the federal government.

In his 150-page judgment yesterday, Judge Noel catalogued gaping contradictions in testimony relating to Mr. Dueck's supposed appearance, age and activities at the time he was purportedly terrorizing Ukrainian citizens.

Judge Noel said several of the key witnesses had no credibility and appeared to have based their accounts on local gossip.

According to the theory of the war crimes prosecutors, Mr. Dueck was a senior officer of the local collaborationist police.  Known as Ivan Ivanovich Dik, they said he helped the German occupying forces round up and execute several dozen civilians and soldiers — including Jews, partisans and Communist functionaries.

Mr. Dueck was admitted to Canada in 1948, and became a Canadian citizen in 1957.  The central question in the case was whether he lied about his wartime activities to successfully immigrate.

In his own testimony, Mr. Dueck said he was a citizen of the USSR, born in a Mennonite community in 1919.  He testified that at the beginning of the war, he was conscripted to serve against the Nazi forces by digging antitank trenches on the front lines.

Mr. Dueck said he arrived in Selidovka for the first time in mid-1942.  When the German occupying army learned that Mr. Dueck spoke German, he said, they forced him to become a translator.  He adamantly denied that his duties involved being a police official or being party to any war crimes.