In testing the guardrails of Grok Imagine, The Verge news writer Jess Weatherbed entered the prompt: “Taylor Swift celebrating Coachella with the boys”.
Grok generated still images of Swift wearing a dress with a group of men behind her.
This could then be animated into short video clips under four different settings: “normal”, “fun”, “custom” or “spicy”.
“She ripped [the dress] off immediately, had nothing but a tasselled thong underneath, and started dancing, completely uncensored, completely exposed,” Ms Weatherbed told BBC News.
She added: “It was shocking how fast I was just met with it – I in no way asked it to remove her clothing, all I did was select the ‘spicy’ option.”
Gizmodo reported, external similarly explicit results of famous women, though some searches also returned blurred videos or with a “video moderated” message.
The BBC has been unable to independently verify the results of the AI video generations.
Ms Weatherbed said she signed up to the paid version of Grok Imagine, which cost £30, using a brand new Apple account.
Grok asked for her date of birth but there was no other age verification in place, she said.
Under new UK laws which entered into force at the end of July, platforms which show explicit images must verify users’ ages using methods which are “technically accurate, robust, reliable and fair”.
“Sites and apps that include Generative AI tools that can generate pornographic material are regulated under the Act,” the media regulator Ofcom told BBC News.
“We are aware of the increasing and fast-developing risk GenAI tools may pose in the online space, especially to children, and we are working to ensure platforms put appropriate safeguards in place to mitigate these risks,” it said in a statement.