Billionaire entrepreneur 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 on Thursday in California Superior Court in San Francisco is a culmination to Musk’s long-simmering opposition to the startup he co-founded and which has since become the face of generative AI, partly due to billions of dollars in funding from Microsoft. Musk has gone on to found his own artificial intelligence startup, xAI, which he launched last July.

Musk in the lawsuit 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 Alphabet Inc’s Google, which Musk said he 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.

OpenAI, Microsoft and Musk did not respond to Reuters requests for comment.