SAN FRANCISCO — A senior lawyer at Twitter submitted his resignation on Thursday, four people familiar with the matter said, becoming the latest in a string of executives to leave the company since Elon Musk took it over nearly six months ago.
The lawyer, Christian Dowell, rose to the top of Twitter’s legal department in recent months after the company’s legal leaders resigned or were fired by Mr. Musk. Mr. Dowell had been intimately involved in Twitter’s recent negotiations with the Federal Trade Commission, two people familiar with those discussions said.
The F.T.C., which currently has oversight over Twitter, is looking into a former executive’s claims that the company has had security problems. The commission accelerated its inquiry after the sudden resignations of three Twitter executives responsible for privacy, security and compliance. They departed Twitter in November, shortly after Mr. Musk acquired the company.
The agency’s investigation into Twitter has intensified in recent months, and is scrutinizing whether the company has the resources to uphold its privacy promises after mass layoffs and resignations.
Mr. Dowell did not respond to a request for comment. Mr. Musk did not immediately respond to a request for comment.
Mr. Musk sought to meet with some of the F.T.C.’s commissioners in recent months to discuss the investigation, two people familiar with his efforts said. Only Christine Wilson, the departing Republican commissioner, accepted his request. Mr. Dowell coordinated Twitter’s responses to the F.T.C.’s inquiries and participated in arranging the meeting, those people said.
Ms. Wilson stepped down from her position last Friday. In a Wall Street Journal opinion piece about her decision to resign, she said Lina Khan, the F.T.C. chair, held “disregard for the rule of law and due process and the way senior F.T.C. officials enable her.”
Mr. Dowell joined Twitter in 2020 after stints at the question-and-answer site Quora and Facebook, and focused on product issues before he was promoted in December, becoming the head of legal overseeing Twitter’s product.
Mr. Dowell’s departure follows a spate of exits by legal and compliance executives at the social media company. On the day that Mr. Musk closed his deal for Twitter in late October, he fired Vijaya Gadde, then the company’s chief legal officer, and its general counsel, Sean Edgett.
In December, Mr. Musk fired James A. Baker, a Twitter lawyer and a former general counsel at the F.B.I., after Mr. Baker played a role in reviewing internal communications about the company’s decision to suppress a 2020 New York Post story about Hunter Biden’s laptop. The billionaire has also sidelined his personal lawyer from working at Twitter and rotated in other legal help from SpaceX, the rocket company he founded and operates.
Beyond the F.T.C. investigation, Twitter is facing a host of lawsuits over unpaid bills for software, vendor services and rent. Former employees have also sued the company, claiming that it violated labor laws during layoffs.
Twitter also sought to pursue legal action against an unknown person who leaked portions of its source code online and obtained a subpoena last month compelling GitHub, the software development collaboration platform that hosted the code, to divulge information about the person.
This week, a German federal body began proceedings to fine Twitter for what it said was the company’s failure to deal with complaints of illegal content. “First I’ve heard about this,” Mr. Musk tweeted on Tuesday about the German legal proceedings.
Mr. Dowell’s resignation comes as Mr. Musk said he was building a “powerful litigation team” at Tesla, his electric carmaker. On Tuesday, he tweeted that this team would go “after the Wall St short-sellers, certain law firms & (sometimes) corrupt regulators who are the true evil.”
Several Twitter executives have submitted their resignations, only to return to work at the company, and it is unclear whether Mr. Dowell might go back to Twitter at some point.
Robin Wheeler, a sales executive, resigned in November but came back and stayed for a few more weeks. It was not immediately clear who at Twitter might inherit Mr. Dowell’s legal responsibilities.