Bloomberg reported that Tesla engineers had been brought in to review Twitter’s code, and that engineering lay-offs were being decided based on employees’ contributions.
Twitter’s top executives, including its chief executive and heads of finance and legal, were reportedly sacked “for cause”, meaning they could be denied a $100m golden goodbye.
The Telegraph has been told that Mr Musk is planning widespread cutbacks at Twitter, although he has not confirmed the scale of the redundancies.
It comes amid concerns from advertisers and civil liberties groups that Mr Musk’s plans to boost free speech on the social network could lead to an increase in hate speech. He is also considering whether to remove permanent bans on hundreds of accounts, which could include former US President Donald Trump.
On Wednesday night, Mr Musk tweeted a poll asking if advertisers should support “freedom of speech” or “political correctness”. Last week, car company GM also paused advertising spending.
Advertising sources have said that a number of major brands are concerned the changes could reduce moderation on the social network and may pull their ads if Mr Musk follows through.
On Thursday, the brewer Carlsberg said it had paused advertising spending on Twitter following Mr Musk’s takeover, the Financial Times reported.
A spokesman for Carlsberg said: “We have advised our brand teams to pause advertising activities and we are monitoring the situation closely.”
This week Interpublic Group, a major advertising company, recommended its clients temporarily pause ad spending on Twitter.
Mr Musk promised civil liberties groups on Monday that he would restore access to content moderation tools on Twitter that had been blocked for some staff since he took over the company, Bloomberg reported.
The Telegraph has contacted Twitter for comment.