The regulator warned that some sexually-explicit images generated and shared by X users using the Grok AI chatbot may amount to intimate image abuse and child sexual abuse material (CSAM).

Ofcom has opened a formal investigation to establish whether X has failed to comply with its legal obligations under the UK’s Online Safety Act 2023.

A finding that X has broken the law could lead to the imposition of fines of up to £18 million (around €20.7 million) or 10 per cent of qualifying worldwide revenue — whichever is greater.

In the most serious cases of ongoing non-compliance, Ofcom can also make an application to a court for ‘business disruption measures’, which could include blocking access to X within the UK.

A spokesperson for Ofcom said: “Reports of Grok being used to create and share illegal non-consensual intimate images and child sexual abuse material on X have been deeply concerning.

“Platforms must protect people in the UK from content that’s illegal in the UK, and we won’t hesitate to investigate where we suspect companies are failing in their duties, especially where there’s a risk of harm to children.

“We’ll progress this investigation as a matter of the highest priority, while ensuring we follow due process.

“As the UK’s independent online safety enforcement agency, it’s important we make sure our investigations are legally robust and fairly decided.”

Ireland’s regulator, Coimisiún na Meán, said last week that it was engaging with the European Commission and An Garda Síochána in relation to Grok.