Hollywood star Scarlett Johansson has said she was left "shocked" and "angered" after OpenAI launched a chatbot with an "eerily similar" voice to her own.

The actress said she had previously turned down an approach by the company to voice its new chatbot, which reads text aloud to users.

When the new model, called Sky, debuted last week commentators were quick to draw comparisons between the chatbot's tone and Johansson's in the 2013 film Her.

OpenAI said on Monday that it would remove the voice, but insisted that it was not meant to be an "imitation" of the star.

However, Johansson accused the company, and its founder Sam Altman, of deliberately copying her voice, in a statement obtained by the BBC on Monday evening.

“When I heard the released demo, I was shocked, angered and in disbelief that Mr Altman would pursue a voice that sounded so eerily similar to mine," she wrote.

"Mr Altman even insinuated that the similarity was intentional, tweeting a single word 'her' - a reference to the film in which I voiced a chat system, Samantha, who forms an intimate relationship with a human."

The actress, who has been nominated for two Academy Awards, said she had been initially approached by Mr Altman about voicing the new chatbot in September.

"[Mr Altman] told me that he felt that by my voicing the system, I could bridge the gap between tech companies and creatives and help consumers to feel comfortable with the seismic shift concerning humans and AI," Johansson wrote.

"He said he felt that my voice would be comforting to people."

But she eventually rejected the offer for personal reasons, she said.

Two days before the Sky chatbot was released, she added, Mr Altman contacted her agent, urging Johansson to reconsider her initial refusal to cooperate with the company.

Adding that she had been forced to hire lawyers, the actress said she had sent two legal letters to the company, to establish how the voice had been made.

"In a time when we are all grappling with deepfakes and the protection of our own likeness, our own work, our own identities, I believe these are questions that deserve absolute clarity," she wrote.

The BBC has approached OpenAI for comment. The company has yet to reply to Johansson's allegations.

But OpenAI said on Monday its "Sky" voice was not intended to be an "imitation" of the star.

"We believe that AI voices should not deliberately mimic a celebrity's distinctive voice," it said in a blog post.

The firm said it was "working to pause" the voice while it addressed questions about how it was chosen in a post on X, formerly Twitter.

In its blog post, OpenAI said the five voices used by its chatbot had been sampled from voice actors it partnered with.

Johansson's legal threats come as the company faces several impending lawsuits.

In December, the New York Times said it planned to launch a lawsuit against the corporation over allegations that it had used "millions" of articles published by the media organisation to train its ChatGPT AI model.

And in September, authors George R R Martin and John Grisham also announced a plan to pursue a claim, over allegations their copyright had been infringed to train the system.