The Alberta Medical Association has passed a unanimous motion supporting a doctor at the centre of an environmental controversy in northern Alberta.

In February, Health Canada officials filed a complaint against Dr. John O'Connor, who raised concerns about high rates of cancers and other illnesses in a community downstream from Alberta's oilsands developments.

Dr. Gerry Keifer, the Alberta Medical Association's president, said Monday that doctors have a right to voice concerns.

"We want to make sure the federal minister of health and public authorities are aware of a physician's professional obligation and his right to speak out when he observes something."

A letter of support for O'Connor has been sent to the College of Physicians and Surgeons of Alberta, as well the the federal and provincial health ministers, Keifer said.

O'Connor alerted the media last year to what he believed was a disproportionately high incidence of colon, liver, blood and bile-duct cancers in patients who live in Fort Chipewyan, a small community downstream from major petroleum refineries.

In filing the complaint against O'Connor with the College of Physicians and Surgeons of Alberta, Health Canada did not explain the action, but said the doctor was causing undue alarm.

First Nations back O'Connor

The complaint has made O'Connor a celebrity of sorts. His name is mentioned at environmental rallies and on internet blogs. Opposition parties, both federally and provincially, have taken up his cause, as have First Nations leaders.

Chief Jim Bouchier, who speaks on behalf of the Athabasca Tribal Council that represents the five First Nations in northeastern Alberta, said O'Connor repeated concerns First Nations people have raised for years.

"In our estimation, Dr. O'Connor is doing things in the best interest of his patients," he said.

"Health Canada as well as other health care providers in the region have failed in their duty and responsibility with respect to ensuring that the interests of the First Nation people are taken care of."

Health Canada still won't talk about why it thinks O'Connor is unduly raising concern, while O'Connor can't talk until the complaint with the the College of Physicians and Surgeons of Alberta is resolved.