Controversial former Sydney doctor and scientist Dr William McBride, whose investigations revealed the dangers of thalidomide in pregnant women, has died aged 91.

The obstetrician was celebrated for alerting the world to the birth defects caused by the morning sickness drug.

However, he fell from grace in the 1990s after being found guilty of scientific fraud over his experiments involving other pregnancy drugs.

Dr McBride's son David McBride paid tribute to his father on Facebook.

"Yesterday my Dad, Dr Bill McBride, passed away peacefully with his wife of 60-odd years beside him, and family nearby," he said.

"Great Doctor, Big Life, Loving Dad and much loved Grandpa.

"Feeling very close to you now Dad, and smiling at all those wonderful memories.

"From Bexley to the world and back, with all your kids in tow."

The President of Thalidomide Australia Incorporated, Lance Fletcher, said Dr McBride's work prevented even more children from suffering the devastating effects of the drug.

"Personally, if he hadn't written into [medical journal] The Lancet the very minute that he did, my mother would have continued to take thalidomide so my deformities would have been more significant," he said.

"Once he put it out there and put it into the Lancet all the links sort of came together.

"There were other doctors around the world looking at these links, but William McBride was the first to actually put it out there to the public."