Alphabet Inc.’s digital city on Toronto’s waterfront is in danger of becoming surveillance city unless data is stripped of personal details from the get go, according to one of the world’s leading privacy experts.

Ann Cavoukian will meet with Waterfront Toronto, the government organization overseeing the project, this week to seek a commitment that information collected will be “de-identified at source.” Cavoukian resigned as an adviser to Sidewalk Labs LLC, a unit of Google parent Alphabet, last month in protest over privacy concerns but said she would consider returning if this principle is ensured.

“If you can’t insist upon data being de-identified at source, you’re going to have a city of surveillance because everybody wants access to personally-identifiable data,” Cavoukian said in an interview. “That’s the treasure trove and that’s the exact opposite of what we want.”

Sidewalk Labs and Waterfront Toronto unveiled a plan to much fanfare a year ago to turn a 4.9-hectare (12-acre) patch of land on Lake Ontario into a “city of the future,” showcasing everything from green-energy systems to new housing techniques. It’s been embroiled in controversy from the start over how data from smartphones, sensors and the like, will be used, with Cavoukian’s resignation the latest twist.

The former information and privacy commissioner of Ontario emphasized that Sidewalk has never pushed back on de-identification at source but said it couldn’t control what other companies would do. “That just set off all the whistles in my head,” Cavoukian said.

She was hired as a paid adviser by Sidewalk Labs last December to embed her “privacy by design” framework in the project. The model holds that privacy must be incorporated into data systems, projects designs and technologies by default and has been used by international organizations including the U.S. Federal Trade Commission.