The Tesla boss has filed an amended lawsuit that now includes Microsoft and LinkedIn co-founder Reid Hoffman as defendants.

Musk is accusing OpenAI and Microsoft of monopolising the artificial intelligence industry and claims they have veered far from the principles upon which OpenAI was founded.

The lawsuit, filed in a California court on Thursday, alleges that OpenAI has transformed from “a tax-exempt charity to a $157billion (£124billion) for-profit, market-paralysing gorgon.”

Musk’s complaint also accuses Microsoft of leveraging its investment in OpenAI to stifle competitors, including his own AI venture, xAI.

“As a result of their unlawful actions, defendants have been unjustly enriched to the tune of hundreds of billions of dollars in value, while Mr Musk has been conned along with the public,” the filing states.

An OpenAI spokesperson dismissed Musk’s claims, saying: “Elon’s third attempt in less than a year to reframe his claims is even more baseless and overreaching than the previous ones.”

They also pointed to earlier emails from Musk, shared publicly, which they said “speak for themselves.”

Microsoft has declined to comment on the matter, while Hoffman has yet to respond to requests for comment.

OpenAI, originally set up as a non-profit to pursue artificial general intelligence, shifted to a “capped profit” model in 2019, allowing it to attract major investment, including $1billion from Microsoft that year. This grew into a multi-billion dollar partnership by 2023.

The lawsuit also targets OpenAI CEO Sam Altman, accusing him of “rampant self-dealing”.

Musk claims the company has become “a closed-source de facto subsidiary” of Microsoft, countering OpenAI’s assertion that he previously supported the shift to a profit-driven model.

Musk’s legal salvo coincides with his appointment by President-elect Donald Trump to help spearhead a government cost-cutting initiative.