Online criminals are claiming to have used Elon Musk’s Grok chatbot to create sexual imagery of children, as a child safety watchdog warned the AI tool risked bringing such material into the mainstream.

The UK-based Internet Watch Foundation (IWF) said users of a dark web forum boasted of using Grok Imagine to create sexualised and topless imagery of girls aged between 11 and 13. IWF analysts said the images would be considered child sexual abuse material (CSAM) under UK law.

“We can confirm our analysts have discovered criminal imagery of children aged between 11 and 13 which appears to have been created using the tool,” said Ngaire Alexander, the head of the IWF’s hotline, which investigates reports of CSAM from members of the public.

X, Elon Musk’s social media platform, has been deluged with images of women and children whose clothes have been digitally removed by the Grok tool, sparking public outcry and condemnation from politicians.

Meanwhile, on Wednesday, the House of Commons women and equalities committee said it would no longer use X for its communications, saying it was no longer appropriate to do so given preventing violence against women and girls was among its key policy areas.

The decision marks the first significant move by a Westminster organisation to exit X in response to the misuse of Grok. While the decision concerned only the committee’s account, some individual members, including the Labour chair, Sarah Owen, have already stopped using X. Another, the Liberal Democrat MP Christine Jardine, said she was leaving the platform, calling the images generated by Grok “the last straw”.

Alexander said the imagery viewed by the IWF has been used to create even more extreme material – known as Category A, which includes penetrative sexual activity – using a different AI tool.

“We are extremely concerned about the ease and speed with which people can apparently generate photo-realistic child sexual abuse material. Tools like Grok now risk bringing sexual AI imagery of children into the mainstream. That is unacceptable,” Alexander added.

Musk’s xAI, which owns Grok and X, has been approached for comment.

Downing Street said “all options were on the table”, including a boycott of X as ministers backed the UK regulator, Ofcom, to take action.

On Wednesday, the prime minister’s official spokesperson said: “X needs to deal with this urgently and Ofcom has our full backing to take enforcement action wherever firms are failing to protect UK users.

“It already has the power to issue fines of up to billions of pounds and even stop access to a site that is violating the law.”

Requests for Grok to manipulate images of women to “put her in a bikini” continued to flood in on X on Wednesday. Despite the warnings of EU and UK regulatory action, there was no evidence that the platform had installed tighter safeguards, and pictures of teenage girls continue to be stripped down digitally at the request of X users, to show them in small, revealing items of underwear, or positioned in sexually explicit poses.

Some users have demanded more extreme content, asking the chatbot to decorate bikinis with swastikas, or requesting alterations to photographs of women so they appear to be victims of abuse. The chatbot has obliged by adding cigarette burns, facial bruising, and blood to some images of women.

The UK’s data watchdog – the Information Commissioner’s Office (ICO) – said it had contacted X and xAI “to seek clarity on the measures they have in place to comply with UK data protection law and protect individuals’ rights”, adding people have “a right to use social media knowing their personal data is being handled lawfully and with respect”.

X has said it takes action against illegal content, including child sexual abuse material, “by removing it, permanently suspending accounts, and working with local governments and law enforcement as necessary”.