Hate speech has risen on Twitter since Elon Musk took over, online safety campaigners have said.
The billionaire claimed hate speech had declined since he bought the site in late October, but research by the Centre for Countering Digital Hate (CCDH) said that was “misleading”.
The number of tweets containing racist and other hateful terms has in fact increased substantially, it said.
CCDH chief executive Imran Ahmed said: “Elon Musk has again been exposed as misleading users and advertisers, claiming mission accomplished despite his clear failure to meet his own self-proclaimed standards to clamp down on vicious bigotry.
“Community standards ensure users feel welcome and advertisers’ brands are safe.
“Advertisers can either enable Mr Musk’s gaslighting, or send a message and stop their marketing dollars enabling the spread of deadly hate.
“It’s time for advertisers to do their bit to counter hate in our societies.”
The data showed that tweets containing a derogatory term for black people were being posted at triple the rate compared to the period before Mr Musk’s takeover.
And tweets containing other racist, homophobic and transphobic terms were also being posted more regularly.
The group analysed tweets from the month preceding Mr Musk’s takeover and compared them with posts in the week leading up to his tweet about hate speech impressions.
The CCDH said Mr Musk’s focus on tweet impressions was obscuring the fact that the number of hateful tweets being hosted by Twitter was actually rising, which it said was a failure to enforce platform community standards.
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Before his takeover, the billionaire businessman said he believed Twitter should allow more free speech and that he would loosen content moderation to enable this to happen.
Mr Musk allowed some previously suspended accounts to return, but has now suspended the account of rapper Ye — formerly known as Kanye West — after he posted an image that appeared to show a symbol combining a swastika and a Jewish Star of David.
Mr Musk said the US rapper had breached rules against incitement to violence.
Some companies have already paused advertising, which for the vast majority of Twitter’s revenue, over concerns about Mr Musk’s approach.
The billionaire recently declared war on iPhone maker Apple's app store, over what he later said was a “misunderstanding”.
Mr Musk met with Apple chief Tim Cook on Wednesday to “resolve” the issue.
"Among other things, we resolved the misunderstanding about Twitter potentially being removed from the App Store," Musk tweeted.
"Tim was clear that Apple never considered doing so."
Mr Musk also tweeted a video clip of "Apple's beautiful HQ" in Cupertino, California, noting that he had a good conversation with Mr Cook.
The Tesla and SpaceX boss has already begun looking for ways to diversify Twitter’s income stream by starting to charge a monthly subscription fee to verify users on the site through its Twitter Blue service.
That roll-out is currently on pause after some bad actors used their verified status to pose as public figures and businesses on the site, in what former head of safety and security Yoel Roth referred to as "a disaster."
Since taking over Twitter last month, Mr Musk has cut about half of Twitter's workforce, including many employees tasked with fighting disinformation, while an unknown number have quit.
He has also reinstated previously banned accounts, including that of former US president Donald Trump.
Describing himself as a "free speech absolutist," Mr Musk has said he believes that all content permitted by law should be allowed on Twitter, describing his actions as a "revolution against online censorship in America."