As Google faces questions today during a congressional hearing on digital privacy, a former Google scientist is asking senators to press the company on its controversial Chinese search engine plans.

Jack Poulson, a former senior research scientist at the company, publicly resigned from Google over concerns about the project, codenamed “Project Dragonfly.” To enter the Chinese market, Google would have to comply with the country’s strict censorship apparatus, a prospect that has led to major criticism from human rights advocates.

“I was compelled to resign my position”

In the letter, which was sent this week to members of the Senate Committee on Commerce, Science, and Transportation, Poulson describes concern at Google regarding the project. “I was compelled to resign my position on August 31, 2018, in the wake of a pattern of unethical and unaccountable decision making from company leadership,” Poulson writes. “This culminated in their refusal to disclose information about Project Dragonfly, a version of Google Search tailored to the censorship and surveillance demands of the Chinese government.”

Poulson writes that the project appears to contradict the company’s stated principles for the use of AI, and that he is able to verify some reported information about the project, much of which has been revealed by The Intercept. “Project Dragonfly,” he writes, included a “prototype interface” that tied users to their phone numbers, and it also blacklisted words like “human rights.” The project was approved after what he describes as “a catastrophic failure of the internal privacy review process.”

Calls privacy review “a catastrophic failure”

“We’ve been investing for many years to help Chinese users, from developing Android, through mobile apps such as Google Translate and Files Go, and our developer tools,” the company said in a previous statement. “But our work on search has been exploratory, and we are not close to launching a search product in China.”

Earlier this month, top Google executives did not appear for a hearing that included Twitter CEO Jack Dorsey and Facebook COO Sheryl Sandberg. Senators criticized the absence, which the company attributed to a misunderstanding over who would be an acceptable witness. Today’s Senate hearing will include Google’s chief privacy officer, Keith Enright, among representatives from other companies. The appearance will be a new opportunity for lawmakers to question Google, and “Dragonfly” will undoubtedly be on the agenda.