OTTAWA (AFP) - A Canadian microbiologist who reassured a frightened nation during the 2003 Sars crisis, has ignited a controversial debate with a posthumous plea on Wednesday for assisted suicide.

Dr Donald Low of Toronto's Mount Sinai Hospital died on Sept 18 at age 68, seven months after being diagnosed with a brain stem tumour.

Eight days before his death, he recorded a video - just released on YouTube - pleading for Canada's laws to be changed, so that he and other terminal patients could choose the time and manner of their death.

Doctor-assisted suicide is illegal in Canada. "I'm going to die. What worries me is how I'm going to die," he said in the video, describing his failing health.

"Am I going to end up being paralysed and have to be carried from the bathroom to the bed, am I going to have trouble swallowing... what the end is going to look like, that's what is bothering me the most." He noted that palliative care made death "a bit easier to face," but could not take away his symptoms.

In the video, Dr Low was critical of opponents of assisted suicide, and said it was an option he would have availed himself of, had it been legal.

"I wish they could live in my body for 24 hours and I think they would change their opinion. I'm just frustrated not being able to have control over my own life, not being able to make the decision for myself when enough is enough.

"Why make people suffer for no reason when there's an alternative. I just don't understand," he said.

A spokesman for Canadian Justice Minister Peter MacKay said the government has no plans to reconsider the issue, noting that a majority of parliamentarians voted in 2010 to maintain the status quo.

"The laws surrounding euthanasia and assisted suicide exist to protect all Canadians, including those who are most vulnerable, such as people who are sick or elderly or people with disabilities," said MacKay's press secretary Paloma Aguilar.

And we "have no intention of reopening this debate," she said.

Dr Low's plea comes 20 years after the Supreme Court rejected terminally ill patient Sue Rodriguez's legal challenge of the ban on physician-assisted suicide.

Since then, new challenges have been filed across the country.

A court in westernmost British Columbia last year struck down the ban calling it discriminatory, disproportionate and overbroad. The federal government is appealing the ruling.

Quebec unveiled in June a proposed law to allow doctor-assisted suicide, expected to be passed into law in the coming months, bumping up against the federal criminal law.

Dr Low's video ends with a message: "He did not have the death he had hoped for, but he died in his wife's arms and he was not in pain." His wife Maureen Taylor described to public broadcaster CBC his last moments.

"I could hear his breathing, as normal, was very laboured, and all of a sudden, I couldn't hear it. And I turned back to him and he had one last breath and I held him and he didn't breathe again anymore," she said.

"But I can tell you that was not a dignified death."