The 39-year-old actress has revealed she previously rejected an approach by the company behind ChatGPT to lend her voice to its new chatbot Sky, which launched last week with people drawing comparisons to its tone and Scarlett's in 2013 movie 'Her'.
In a lengthy statement through her rep, she said: "Last September, I received an offer from [OpenAI CEO] Sam Altman, who wanted to hire me to voice the current ChatGPT 4.0 system.
"He 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".
"He said he felt that my voice would be comforting to people. After much consideration and for personal reasons, I declined the offer".
"Nine months later, my friends, family and the general public all noted how much the newest system named 'Sky' sounded like me".
Scarlett admitted she was left "shocked" and "angered" by the apparent similarities.
She continued: "When I heard the released demo, I was shocked, angered and in disbeleief that Mr. Altman would pursue a voice that sounded to eerily similar to mine that my closest friends and news outlets could not tell the difference.
"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".
She claimed that Altman contacted her agent days before the demo was released and asked her to "reconsider".
She said: "Before we could connect, the system was out there..."
"As a result of their actions, I was forced to hire legal counsel, who wrote two letters to Mr. Altman and OpenAI, setting out what they had done and asking them to detail the exact process by which they created the 'Sky' voic".
"Consequently, OpenAI reluctantly agreed to take down the 'Sky' voice".
Taking aim at the general rise of artificial intelligence, Scarlett insisted the public "deserves absolute clarity".
She explained: "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.
"I look forward to resolution in the form of transparency and the passage of appropriate legislation to help ensure that individual rights are protected."
In a statement to The Verge, Altman said: "The voice of Sky is not Scarlett Johansson's, and it was never intended to resemble hers".
"We cast the voice actor behind Sky's voice before any outreach to Ms. Johansson.
"Out of respect for Ms. Johansson, we have paused using Sky's voice in our products. We are sorry to Ms. Johansson that we didn't communicate better."