The chief executive of OpenAI - the firm behind viral chatbot ChatGPT - has been ousted after the board said it no longer has confidence in him.
Sam Altman is to depart and will be replaced in the interim by Mira Murati, who is currently chief technology officer for the artificial intelligence company.
In a statement on Friday, OpenAI said the move follows a "deliberative review process by the board" which concluded that Altman "was not consistently candid in his communications with the board".
The statement said Altman's behaviour was hindering the board's ability to exercise its responsibilities.
Posting on social media following the announcement, Altman wrote: "I loved my time at OpenAI.
"It was transformative for me personally, and hopefully the world a little bit.
"Most of all, I loved working with such talented people. (I) will have more to say about what's next later."
Altman helped start OpenAI as a non-profit research laboratory in 2015.
But in the past year, he was thrust into the global spotlight as the face of OpenAI after ChatGPT exploded into public consciousness.
On Thursday, he took part in a CEO summit at the Asia-Pacific Economic Co-operation conference in San Francisco, where OpenAI is based.
Altman predicted AI will prove to be "the greatest leap forward of any of the big technological revolutions we've had so far".
But he also acknowledged the existential threat posed by the quantum leaps being taking by computers, and the need for guardrails to protect humanity.
"I really think the world is going to rise to the occasion and everybody wants to do the right thing," Altman said.