An elderly Waterloo man, who allegedly participated in Nazi death squads during the Second World War, has lost a two-decade-long legal battle to keep his Canadian citizenship and avoid deportation.In a decision released Wednesday, the Federal Court of Appeal dismissed Helmut Oberlander’s bid to appeal a 2018 Federal Court ruling that found Ottawa had acted reasonably in stripping him of his citizenship.Helmut Oberlander, right, and his wife Margret, left, and daughter Irene Rooney, centre behind, are shown leaving the courthouse in Kitchener in 2003. Oberlander has lost a two-decade-long legal battle to keep his Canadian citizenship and avoid deportation for Nazi war activities. (Peter Lee / THE CANADIAN PRESS FILE PHOTO)Helmut Oberlander, shown in 2004, has denied taking part in any atrocities committed by the Nazi death squad he was part of during the Second World War. (Mathew McCarthy / The Record File Photo)Helmut Oberlander in a uniform of the German Sicherheitsdienst (SD), the internal security service of the SS. (COURTESY OF FEDERAL COURT OF CANADA)The decision was welcomed by Canada’s Jewish community and the Liberal government, which must now decide whether or not to issue a removal order to deport Oberlander to Germany or Ukraine. The government said it is currently reviewing the situation and examining next steps.“This closes the book on Nazi enablers in this country,” said Bernie Farber, former CEO of the Canadian Jewish Congress and a human rights advocate. “He participated in and enabled the work of the most notorious Nazi killing unit. It took so long for justice to be carried out. He never had a right to be in this country.”The Ukraine-born Oberlander, now 95, has steadfastly maintained he was just 17 when he was forced to join the Nazi death squad Einsatzkommando 10a, known as Ek 10a, which was responsible for killing close to 100,000 people, mostly Jewish. He has argued that he served as an interpreter and that there is no evidence he took part in any atrocities, but the federal government contends that because he was part of the squad, he was complicit in the crimes.“This decision further supports our mandate to deny safe haven in Canada to war criminals and persons believed to have committed or been complicit in war crimes, crimes against humanity, or genocide,” said Mathieu Genest, spokesperson for Immigration Minister Ahmed Hussen. “It is important that applicants be truthful and transparent when applying for Canadian Citizenship.”Oberlander and his wife came to Canada in 1954, and he became a citizen six years later. He did not disclose his wartime experience on his citizenship application.The legal case against Oberlander began in 1995. In 2001, he was stripped of his citizenship by the federal cabinet after a court found he had lied about his service as an interpreter with the Nazi death squad — a decision that was overturned in 2004 and sent back to cabinet for reconsideration.In 2007, he was stripped of his citizenship again and faced another deportation hearing. In 2009, the Federal Court of Appeal ruled that the federal cabinet must again revisit the decision to strip Oberlander of his citizenship and consider whether he was forced to join the Nazis under duress.Then in December 2012, Ottawa filed another order-in-council to revoke his citizenship. The move was challenged by Oberlander in Federal Court and dismissed in 2015. In June 2017, the government revoked the retired land developer’s citizenship for the fourth time, and another legal challenge ensued. In November, the court ruled in favour of the government and Oberlander once again took the case to the appeal court.In his latest appeal, Oberlander had argued that Justice Michael Phelan was biased because the judge had previously — in 2008 — made a finding in his case that he contributed to war crimes or crimes against humanity.“The mere fact a judge was involved in an earlier decision and made findings adverse to a party does not, in and of itself, give rise to a reasonable apprehension of bias,” wrote Justice Richard Boivin in a unanimous decision on behalf of colleagues Donald Rennie and Yves De Montigny in closing the file.“To proceed from the assumption that a prior adverse finding of the fact was made … constitutes a foundation for bias would have serious implications for the administration of justice.”In a statement to the Star Thursday, Oberlander’s daughter, Irene Rooney, said the family was devastated with the appeal court decision.“The case has been in the Canadian courts for 24 years and is of national importance. We have previously won three times in the Federal Court of Appeal,” she wrote. “Mr. Oberlander is now 95 years old. He has health issues. He wants nothing more than to have his Canadian citizenship and his reputation restored. He was proudly granted his citizenship in 1960, almost 60 years ago, and has had to endure government challenges for 24 years despite major victories in the Canadian courts.”Farber said he is “both relieved and troubled” that the case has dragged on for so long.“It sent out the wrong message that if you committed this kind of crime, you still got to stay in Canada for decades if you know how to play the system,” he said.“Age should not be an excuse in matters of enabling the Nazi war machine. Let us remember these people as they were at the time, young, committed bullies of a brutal murderous regime. Many people were murdered simply because they were Jewish. They never had the opportunity to see life. This crime cannot be forgiven.”Oberlander’s lawyer Ronald Poulton said the family is considering an appeal to the Supreme Court of Canada, which must be filed in 60 days.With files from Debra Black and The Canadian PressNicholas Keung is a Toronto-based reporter covering immigration. Follow him on Twitter: @nkeungTOP STORIES, DELIVERED TO YOUR INBOX.