Canada's former ambassador to Iran has said he feels slighted by the film about the 1979 hostage crisis.
Ken Taylor, who protected Americans at great personal risk, says if Argo wins the Oscar for best picture there would be something wrong with director Ben Affleck if he did not mention Canada.
Mr Taylor kept the six Americans hidden at the embassy in Tehran and facilitated their escape, and he became a hero in Canada and the US after. But he says he continues to feel slighted by a film that makes Canada look like a meek observer to CIA heroics in the rescue.
Affleck's CIA thriller Argo is widely expected to win the best-picture trophy.
Mr Taylor said that if Affleck does not say something in his acceptance speech "then it's a further reflection" on him. He added: "In general it makes it seem like the Canadians were just along for the ride. The Canadians were brave. Period."
He noted that Jimmy Carter, the US President at the time, said on Thursday night that "90% of the contributions to the ideas and the consummation of the plan was Canadian" but the film "gives almost full credit to the American CIA".
Mr Taylor said: "There would be no movie without the Canadians. We took the six in without being asked so it starts there. And the fact that we got them out with some help from the CIA then that's where the story loses itself. I think Jimmy Carter has it about right, it was 90% Canada, 10% the CIA."
Affleck said he thought his issue with Mr Taylor had been resolved.
"I admire Ken very much for his role in rescuing the six house guests. I consider him a hero. In light of my many conversations as well as a change to an end card that Ken requested I am surprised that Ken continues to take issue with the film," Affleck said in a statement.
"I spoke to him recently when he asked me to narrate a documentary he is prominently featured in and yet he didn't mention any lingering concerns. I agreed to do it and I look forward to seeing Ken at the recording."