Scarlett Johansson has become the latest high-profile victim of a seemingly unauthorised deepfake advert.

A version of the Marvel actress created using artificial intelligence (AI) reportedly appeared in an online promotion for a firm called Lisa AI, which lets users create avatars and images using text prompts.

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A lawyer for Johansson said the company had used her likeness without permission, using footage from a campaign she did with fundraising company Omaze.

The ad was seen on X, formerly known as Twitter, but appears to have since been removed.

Variety reported that the promo had included a disclaimer under the image of Johansson, which said: “Images produced by Lisa AI. It has nothing to do with this person.”

But Johansson’s lawyer Kevin Yorn warned: “We do not take these things lightly.

“Per our usual course of action in these circumstances, we will deal with it with all legal remedies that we will have.”

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Johnson joins the likes of Tom Hanks and Tom Cruise in having her likeness leveraged by advertisers using AI.

Last month, Hanks told his 9.5 million Instagram followers not to fall for an ad that appeared to use his face but was actually a deepfake.

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AI has been a major issue in the recent Hollywood strikes, with both US actors and writers calling for increased safeguards against unauthorised use of their likenesses and works.

The issue of deepfakes has also been on the agenda at this week’s AI safety summit in the UK, amid concerns it could wreak havoc during major elections next year – including in Britain and the US.