Is Facebook's security chief leaving after clash over Russian disinformation?

Rumour has it that Facebook's chief information security officer Alex Stamos is leaving the company, after internal disagreements over how the social networking giant should deal with its role in spreading disinformation.

However, in a tweet, Stamos said that he was still employed and that his role had changed to "exploring emerging security risks and working on election security".

"Despite the rumours, I'm still fully engaged with my work at Facebook. It's true that my role did change. I'm currently spending more time exploring emerging security risks and working on election security," he wrote on Twitter.

Stamos had been a strong advocate inside the company for investigating and disclosing Russian activity on Facebook, often to the dislike of other top executives, including Sheryl Sandberg, the social network's chief operating officer, according to The New York Times.

After his day-to-day responsibilities were reassigned to others in December 2017, Stamos said he would leave the company.

He was persuaded to stay through August to oversee the transition of his duties.

He has been overseeing the transfer of his security team to Facebook's product and infrastructure divisions.

His group, which once had 120 people, now has three, the current and former employees told The New York Times.

Mark Zuckerberg, Facebook's chief executive and co-founder, Sandberg and other company leaders have struggled to address a growing set of problems in the company in recent times, including Russian interference on the platform.

The rise of false news, and the disclosure recently that 50 million of its user profiles had been harvested by Cambridge Analytica, a voter-profiling company that worked on President Trump's election campaign, are other key issues which have emerged.