Google CEO Sundar Pichai has condemned portions of a controversial memo sent by a male engineer at the company who argued that women are not biologically fit for tech roles.

Reuters and Bloomberg reported Tuesday that the engineer had been fired, citing emails they received from him. A Google spokesperson declined to comment on the reports.

In an email to Google employees on Monday, Pichai wrote that parts of the 3,300-word manifesto crossed the line by "advancing harmful gender stereotypes" in the workplace.

"Our job is to build great products for users that make a difference in their lives," he wrote in the email, which was seen by CNNMoney. "To suggest a group of our colleagues have traits that make them less biologically suited to that work is offensive and not OK."

Pichai said he was cutting his family vacation short to return to the office.

Related: Google's open culture tested by engineer's anti-diversity memo

"Clearly there's a lot more to discuss as a group," he wrote. "Including how we create a more inclusive environment for all."

Reactions to the memo inside Google have been fierce and divisive. Some employees used an internal discussion group to call for the engineer who wrote it to be fired, according to a source inside the company. Others have supported the employee's right to voice his opinions, if not supporting the opinions themselves.

Google (GOOGL) has prided itself as an environment that encourages openness and diversity of opinions. But Pichai said that sections of the memo violate the company's Code of Conduct, which requires "each Googler to do their utmost to create a workplace culture that is free of harassment, intimidation, bias and unlawful discrimination."

Related: Biology isn't why tech is a boy's club

A source inside the company told CNNMoney that when an employee violates the company's code of conduct, it often results in firing.

Pichai also said in his email that there are Google employees who are questioning whether they can safely express their opinions, especially ones that might fall into a minority.

"They too feel under threat, and that's not OK," he wrote. "People must feel free to express dissent."

-- Seth Fiegerman and Sara Ashley O'Brien contributed to this report.