A senior privacy expert has quit a smart city project launched by Google subsidiary Sidewalk Labs, claiming that her privacy recommendations were ignored.

Former Ontario privacy commissioner Ann Cavoukian resigned last week over concerns that the "treasure trove" of data collected in the $40m smart city project could identify individuals and leave them open to a cyber attack.

Ms Cavoukian had worked on a privacy by design framework for the project to make sure that citizens' personal data would be protected.

In a meeting last week, Sidewalk Labs admitted that although it is committed to protecting user identity, other businesses in the project may not be.

“I felt I had no choice because I had been told by Sidewalk Labs that all of the data collected will be de-identified at source,” she told Global News.

"I imagined us creating a Smart City of Privacy, as opposed to a Smart City of Surveillance."

The smart city project has been mired in controversy since Sidewalk Labs was commissioned in October 2017 to revitalise the Toronto waterfront.

Former BlackBerry chief executive Jim Balsillie called the project "a colonising experiment in surveillance capitalism" earlier this month and accused it of making irreversible decisions that will have major negative effect on all Canadians.