Facebook Chief Information Security Officer Alex Stamos is reportedly leaving after disagreements over how the social media network should handle the spread of disinformation, the New York Times reported.
In a tweet, Stamos said he was still employed, but that his role had changed to "exploring emerging security risks and working on election security."
Stamos has been a strong advocate for disclosing Russian activity on Facebook.
The Times report said that Stamos's roles had been reassigned in December, but Facebook persuaded him to stay on until August. In a tweet, Reuters independently reported that Stamos would leave in August.
Facebook did not immediately return CNBC's request for comment.