“This situation is causing tremendous pain to our entire family.”
In a statement seen by the BBC, Ms Altman claimed the abuse, which took place over many years, included rape.
The lawsuit added that the last incident of alleged abuse occurred when Mr. Altman was an adult, but she was still a minor.
The lawsuit sought a jury trial and more than $US75,000 ($60,100) in damages.
Ms Altman has previously made similar allegations against her brother on social media sites such as X.
Mr. Altman is one of the most famous figures in the world of technology.
In late 2022, OpenAi launched ChatGPT, a generative artificial intelligence (AI) chatbot.
Additional reporting by Lily Jamali
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