Sam Altman's sister, Ann Altman, has filed a lawsuit claiming that he regularly sexually harassed her between 1997 and 2006.
The lawsuit, filed on January 6 in the U.S. District Court for the Eastern District of Missouri, alleges that the abuse began when she was three years old and Sam Altman was 12.
Mr. Altman, who is the CEO of OpenAI, the company that created the ChatGPT artificial intelligence software, denied the accusations in a joint statement with his mother and two brothers.
"All these statements are completely false," the statement said. "Caring for a family member facing mental health challenges is incredibly complex," they added.
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Mr. Altman said that he provides his sister with monthly financial support, pays her bills and rent, and even offered to buy her a house, but she "continues to demand more money from us."
However, Ms. Altman claims that her brother "cared for and manipulated" her, engaging in sexual actions for several years, including "rape, sexual violence, corruption, sodomy, and beating," according to court documents reviewed by BBC.
Ms. Altman stated that she suffered "serious physical injuries," severe emotional distress, and depression.
She added that she was forced to undergo numerous medical and psychiatric treatments for her injuries.
In the United Kingdom, victims or alleged victims of sexual crimes have the right to lifetime anonymity. However, UK laws granting this right do not apply in the United States.
"For many years, we have tried in various ways to support Annie and help her find stability," Mr. Altman said, adding that he had sought "professional advice" on how to "support himself" without "enabling harmful behavior."
"This situation brings immense pain to our entire family," the statement said.
The lawsuit states that the last instance of alleged abuse occurred when Mr. Altman was already an adult, while Ann Altman remained a minor.
Ms. Altman had previously made similar accusations against her brother on social media platforms like X.
Billionaire Sam Altman, who married his partner Oliver Malcher in 2024, is one of the most well-known figures in the technology world.
In late 2022, OpenAI launched its generative AI chatbot ChatGPT, which gained widespread recognition for its ability to generate computer code, emails, recipes, and various other forms of text — as well as images — based on user prompts.
In 2024, Sam Altman returned as CEO of OpenAI just days after being fired by the board, surviving a coup attempt.