Sam Altman's sister has accused the OpenAI CEO of sexually abusing her for nearly a decade in a lawsuit filed in federal court.

Ann Altman, 30, alleged that Sam Altman abused and molested her while they were growing up in Missouri from the late 1990s to the early 2000s.

According to the lawsuit filed Monday, the alleged abuse began when she was 3 years old and the last incident allegedly occurred when he was an adult but she was still a minor. Ann Altman previously claimed on social media that Sam Altman abused her.

Sam Altman, 39, posted a statement on behalf of himself, his mother and brothers on X on Tuesday, calling the claims "completely false." "Our entire family is deeply saddened by this situation," the statement said.

Sam Altman, a longtime Silicon Valley entrepreneur and investor, gained a global reputation with the massive success of artificial intelligence startup OpenAI’s ChatGPT chatbot, which sparked an AI frenzy with its release in late 2022.

Bloomberg News last year estimated Sam Altman's personal wealth at more than $2 billion, including VC funds and startup investments. He has said several times that he owns no stake in OpenAI.

Under Missouri state law, plaintiffs can bring claims for child sexual abuse until age 31. Ann Altman is suing for damages, claiming she has experienced severe emotional distress and is racking up medical bills related to her mental health treatment.