An advertiser exodus from Elon Musk’s X gathered pace on Friday, with Apple, Disney, Comcast, Paramount and Warner Bros all pausing spending on the social media platform amid concerns about antisemitic content, according to the Financial Times.

Musk, who bought X last year for $44bn, has drawn criticism for endorsing an antisemitic post on the platform earlier this week. Meanwhile, a report from left-leaning non-profit group Media Matters on Thursday found advertisements for top brands — including Apple, IBM, Oracle and Comcast’s Xfinity, a telecoms company, and Bravo, the TV network — next to posts touting “pro-Nazi” views.

The companies’ decisions follow IBM, which on Thursday announced it was pulling global advertising from the platform. Apple was the fourth-largest advertiser on X in the year to date, according to Sensor Tower data.

Media Matters released another report on Friday showing that ads for companies including Amazon, NBA Mexico, and NBCUniversal’s brand agency had appeared next to content with white nationalist tags.

On Saturday, Musk said that he would sue the group for what he claimed was a “fraudulent attack” on X.

Amazon and NBA did not immediately respond to requests for comment.

The spending cull by major brands will hamper efforts by chief executive Linda Yaccarino, hired by X in June, to win back marketers after many pulled their spending from the platform in the wake of Musk’s takeover.

Those companies were increasingly concerned their adverts would be placed next to toxic content after Musk relaxed the site’s moderation policies and fired many staff overseeing platform safety. Ad revenues fell about 50 per cent as a result, the billionaire said in July.

Since then, Yaccarino has been on a charm offensive, meeting with advertisers and agencies to reassure them that the company was investing more in safety. But critics warn she has little power to stop Musk himself from tweeting controversial posts, which also drives away advertisers.

The loss of Comcast marks a particular blow, as Yaccarino worked as the head of advertising at one of its subsidiaries, NBCUniversal, before joining X.

On Wednesday Musk, a self-declared “free speech absolutist”, touted an antisemitic conspiracy theory on X, drawing opprobrium. A White House spokesperson released a statement about his comments on Friday, condemning the “abhorrent promotion of antisemitic and racist hate”.

Apple’s decision to pull advertising from the platform could have implications for its commercial relationship with X, and comes as Musk’s site has been cutting costs in an attempt to improve its finances. Already, in November last year, Musk claimed the iPhone maker was pulling advertising and threatening to remove the platform from its App Store, asking his followers: “Do they hate free speech in America?” A meeting between the controversial billionaire and Apple chief executive Tim Cook later calmed the dispute.

Apple’s decision was first reported by Axios, and the New York Times first reported Disney’s move.

X declined to comment.

On Thursday, following the FT’s reporting that IBM had culled its spending on the platform, Yaccarino tweeted: “X’s point of view has always been very clear that discrimination by everyone should STOP across the board . . . When it comes to this platform — X has also been extremely clear about our efforts to combat antisemitism and discrimination.”