March 20 (Reuters) – A federal judge on Friday dismissed a lawsuit by Sam Altman’s sister accusing the billionaire OpenAI chief executive of sexually abusing her more than two decades ago, but said she can try suing under a different legal theory.
The judge also said Sam Altman, who has denied Annie Altman’s accusations, may countersue his sister for defamation.
U.S. District Judge Zachary Bluestone in St. Louis said Annie Altman cannot pursue sexual assault and sexual battery claims over her brother’s alleged abuse between 1997 and 2006, because those claims expired in 2008.
He said Annie Altman will be allowed to file an amended complaint stating a claim under Missouri’s Childhood Sexual Abuse statute.
Sam Altman’s defamation counterclaim stemmed from posts between 2021 and 2024 on social media, including X and TikTok, where Annie Altman referred to alleged abuse, usually without mentioning his name. These included videos that said she was “touched by older siblings” and that “an almost tech billionaire” molested her.
Bluestone said such statements “require only a reasonable inference” that Sam Altman was the accused perpetrator, and that he can try to prove defamation by showing his sister acted with actual malice.
Ryan Mahoney, a lawyer for Annie Altman, said she will promptly file an amended complaint and continue gathering evidence. A lawyer for Sam Altman declined to comment.
Annie Altman sued her brother in January 2025 over alleged abuse at the family home in suburban Clayton, Missouri, beginning when she was three and her brother was 12.
Sam Altman, now 40, and his family have said his sister has mental health challenges.
In a court filing, he said his family is “deliberate and thoughtful” in helping Annie Altman, including through monthly financial support, but the lawsuit amounted to extortion.
Sam Altman co-founded OpenAI and became a face of the artificial intelligence boom following the 2022 release of the AI chatbot ChatGPT.
Another co-founder, Elon Musk, is suing over OpenAI’s conversion to a for-profit company and seeking as much as $134.5 billion in damages from OpenAI and Microsoft, one of its backers. Jury selection is scheduled for April 27.
Sam Altman is worth $3.4 billion, according to Forbes magazine.
(Reporting by Jonathan Stempel in New YorkEditing by Rod Nickel)
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