A Canadian judge has refused to review an order to revoke the citizenship of a former Nazi death-squad collaborator. The Federal Court in Vancouver rejected Helmut Oberlander's claim that the Canadian government had erred in finding him complicit in atrocities during World War II. The court also ruled that he had hid his involvement when applying for Canadian citizenship in 1960. The decision means Oberlander can be expelled from the country. The 84-year-old man, who was born in the Ukraine, served as an interpreter for a Nazi death squad during the war.