Elon Musk’s AI tool Grok will no longer be able to edit photos of real people to show them in revealing clothing in jurisdictions where it is illegal, after widespread concern over sexualised AI deepfakes.

“We have implemented technological measures to prevent the Grok account from allowing the editing of images of real people in revealing clothing,” reads an announcement on X.

Reacting to the ban, the UK government claimed “vindication” after Prime Minister Sir Keir Starmer called on X to control its AI tool.

A spokesperson for UK regulator Ofcom said it was a “welcome development” – but added its investigation into whether the platform had broken UK laws “remains ongoing”.

“We are working round the clock to progress this and get answers into what went wrong and what’s being done to fix it,” they said.

Technology Secretary Liz Kendall also welcomed the move but said she would “expect the facts to be fully and robustly established by Ofcom’s ongoing investigation”.

X’s change was announced hours after California’s top prosecutor said the state was probing the spread of sexualised AI deepfakes, including of children, generated by the AI model.

“We now geoblock the ability of all users to generate images of real people in bikinis, underwear, and similar attire via the Grok account and in Grok in X in those jurisdictions where it’s illegal,” X said in its statement..

It also reiterated that only paid users will be able to edit images using Grok on its platform.

This will add an extra layer of protection by helping to ensure that those who try and abuse Grok to violate the law or X’s policies are held accountable, according to the statement.

With NSFW (not safe for work) settings enabled, Grok is supposed to allow “upper body nudity of imaginary adult humans (not real ones)” consistent with what can be seen in R-rated films, Musk wrote online on Wednesday.

“That is the de facto standard in America. This will vary in other regions according to the laws on a country by country basis,” said the tech multi-billionaire.

Musk had earlier defended X, posting that critics “just want to suppress free speech” along with two AI-generated images of UK Prime Minister Sir Keir Starmer in a bikini.

It is unclear how his platform will implement location-based blocks on Grok’s ability to edit images of real people to create sexualised imagery, and whether users would be able to get around them.

People seeking to circumvent similar geoblocks on features or content often look to tools such as virtual private networks (VPNs), which can disguise their location online to allow them to use the internet as if they are in a different country.

VPN app downloads spiked in the UK last year after porn sites were required to start checking the age of visitors to comply with the Online Safety Act.

X’s change of policy has been welcomed by campaigners and experts – though they point out for some victims the damage has already been done.

Clare McGlynn, a law professor at Durham University, said it had come “too late for the thousands of women who have been victimised and whose images are still online”.

Andrea Simon, director of the End Violence Against Women Coalition (EVAW), said while it remained to be seen how X would implement its changes, it showed “how victims of abuse, campaigners and a show of strength from governments can force tech platforms to take action”.

“But it can’t stop here – given the evolving nature of AI-generated harms, tech platforms must be required to take proactive preventative action,” she said.

Ofcom said on Monday it would investigate whether X had failed to comply with UK law over the sexual images.

And if X does not comply, Ofcom could seek a court order to force internet service providers to block access to the site in the UK altogether.

Earlier this week, Sir Keir warned X could lose the “right to self regulate” amid a backlash over the AI images, but later in the week said he welcomed reports that X was taking action to address the issue.

The prime minister said he would “take the necessary measures” and strengthen legislation if X failed to act.

Policy researcher Riana Pfefferkorn said she was surprised X took so long to deploy the new Grok safeguards and that the editing features should have been removed as soon as the abuse began.

Questions remain on how X will enforce its new policies, such as how the AI model will know if an image is of a real person and what actions it will take when users break the rules, said Pfefferkorn.

Musk has not presented the company in a serious light either, she said, adding that it would help if he stopped “doing things like re-posting an AI image of Keir Starmer in a bikini.”

Additional reporting by Katy Bailes