Elon Musk has sued ChatGPT-maker OpenAI and its CEO Sam Altman, saying they abandoned the startup’s original mission to develop artificial intelligence for the benefit of humanity and not for profit.

The lawsuit filed late in San Francisco is a culmination to the billionaire’s long-simmering opposition to the startup he co-founded and has since become the face of generative AI, partly due to the billions of dollars in funding from Microsoft (MSFT.O), opens new tab.

Musk alleged a breach of contract, saying Altman and co-founder Greg Brockman originally approached him to make an open source, non-profit company, but the startup established in 2015 is now focused on making money.

Recounting OpenAI’s founding, Musk said the three men had agreed to work on artificial general intelligence (AGI), a concept that machines could handle tasks like a human, but in a way that would “benefit humanity”, according to the lawsuit.

OpenAI would also work in opposition to Google (GOOGL.O), opens new tab, which Musk believed was developing AGI for profit and would pose grave risks.

Instead, OpenAI “set the founding agreement aflame” in 2023 when it released its most powerful language model GPT-4 as essentially a Microsoft product, the lawsuit alleged.

Musk has sought a court ruling that would compel OpenAI to make its research and technology available to the public and prevent the startup from using its assets, including GPT-4, for the financial gains of Microsoft or any individual.

The billionaire is also seeking a ruling that GPT-4 and a new and more advanced technology called Q* would be considered AGI and therefore outside of Microsoft’s license to OpenAI.

Musk, who runs Tesla(TSLA.O), opens new tab and rocket maker SpaceX and bought Twitter for $44 billion in October 2022, stepped down from OpenAI’s board in 2018 and has on several occasions called for regulation on AI.