Google hit with lawsuit over gender pay gap

US tech giant Google is facing a lawsuit from three former employees, who allege the company pays women less for the same work.

The Alphabet-owned company has seen its employment practices come under scrutiny in recent months after a memo circulated by one of its staff members wrote a memo setting out a genetic case why men tended to earn more than women.

The memo opened a wider debate about the gender pay gap in Silicon Valley tech firms, something commented on by one of those women bringing the lawsuit, former Google engineer Kelly Elis.

"It is time to stop ignoring these issues in tech," Elis said on Twitter.

"My hopes for the Google suit: to force not only Google, but other companies to change their practices and compensate EVERYONE fairly."

Google said it would review the lawsuit in detail, but disagrees with the allegations at the centre of it.

"Job levels and promotions are determined through rigorous hiring and promotion committees, and must pass multiple levels of review, including checks to make sure there is no gender bias in these decisions. And we have extensive systems in place to ensure that we pay fairly," said a spokesperson for the company.