Google CEO Sunder Pichai has reportedly cut his vacation short to deal with the crisis over an anti-diversity "manifesto" that went viral inside the company and infuriated thousands of employees.

The tech giant has also reportedly fired the engineer who wrote the 10-page memo, which claimed that "the representation gap between men and women in software engineering persists because of biological differences between the two sexes". 

According to a report in CNNMoney on Tuesday, Pichai condemned portions of the controversial memo that argued that women are not "biologically fit" for tech roles.

Pichai said 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 an email.

"To suggest a group of our colleagues have traits that make them less biologically suited to that work is offensive and not OK. Clearly there's a lot more to discuss as a group, including how we create a more inclusive environment for all," Pichai added.

The Google CEO also said that there are 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. People must feel free to express dissent," he wrote.

Meanwhile, media reported on Tuesday that the engineer, identified as James Damore who wrote the manifesto, has been fired.

According to the Guardian, a Google spokesperson declined to comment on these reports.

On Saturday, online news website Motherboard reported that an anti-diversity manifesto, written by a Google engineer, suggested that the company should halt initiatives aimed at increasing gender and racial diversity within the company and instead focus on "ideological diversity". 

It also said Google should not offer programmes for under-represented racial or gender minorities.

Danielle Brown, Google's new Vice President of Diversity, Integrity and Governance, later issued a statement to Google employees in response to the viral memo.

"I value diversity and inclusion, am not denying that sexism exists, and don't endorse using stereotypes. When addressing the gap in representation in the population, we need to look at population level differences in distributions," she said.

"If we can't have an honest discussion about this, then we can never truly solve the problem. Psychological safety is built on mutual respect and acceptance, but unfortunately our culture of shaming and misrepresentation is disrespectful and unaccepting of anyone outside its echo chamber," Brown added. 

Brown thanked her fellow Googlers for bringing up the issue and vouched for a need to change.

Last month, Google emerged victorious in its fight with the US Department of Labour over supplying pay gap data. The department alleged that the tech giant tried to restrict media coverage of the gender discrimination case. Google was accused of systematically underpaying women.