Elon Musk accuses OpenAI of breaching charitable trust and prioritising profit over AI safety and nonprofit values.

Lawyers for OpenAI and Elon Musk began closing arguments in a landmark trial that could impact the future of the ChatGPT maker.

On Thursday, each side presented a concluding statement to jurors, who will decide whether OpenAI and its leaders profited from a venture that was meant to be a “charity”.

The lawsuit was brought by Musk, the world’s richest man and the founder of a rival artificial intelligence (AI) model, Grok.

Musk sued OpenAI, its CEO Sam Altman and its president Greg Brockman, alleging that the company strayed from its founding mission to build AI that was safe and beneficial to humanity.

Musk was not present for the closing statements on Thursday, as he is currently in China on a diplomatic visit with United States President Donald Trump.

His lawyer, Steven Molo, used his final remarks to accuse OpenAI of breaching its charitable trust by enriching investors and insiders at the nonprofit’s expense. He also sought to paint Altman as untrustworthy.

“I confronted Sam Altman with the fact that five witnesses in this trial, all people that he’s known for years and worked with, called him a liar under oath. Liar’s a very powerful word in a courtroom,” Molo said.

The five people Molo referenced were Musk; Ilya Sutskever, OpenAI’s former chief scientist; former OpenAI chief technology officer Mira Murati; and former board members Helen Toner and Tasha McCauley. Musk invested $38m in OpenAI’s early years.

“Sam Altman’s credibility is directly at issue in this case,” Molo said.

The lawsuit also accuses Microsoft, which invested $1bn in OpenAI in 2019 and another $10bn in 2023, of aiding and abetting OpenAI’s wrongful conduct.

“Microsoft was aware of what OpenAI was doing every step of the way,” Molo said.

OpenAI’s lawyers pushed back, arguing that Musk waited too long to claim the company breached its founding agreement. Part of the defence team, Sarah Eddy, suggested that it was Musk who was unreliable.

“Mr Musk is the one whose testimony is contradicted by every other witness and by all the documents,” Eddy said.

Eddy added that, by 2017, everyone associated with OpenAI — including Musk, who was still on its board — knew it needed more money to fulfil its mission than it could raise as a nonprofit.

She also indicated that Musk himself hoped to profit from the company.

“Mr Musk wanted to turn OpenAI into a for-profit company that he could control,” she said. “But the other founders refused to turn the keys of AGI [artificial general intelligence] over to one person, let alone Elon Musk.”

The question of whether the lawsuit was filed within the statute of limitations may turn out to be a key point.

In a court filing last month, Judge Yvonne Gonzalez Rogers wrote that “if the jury finds that Musk failed to file his action within the statute of limitations, it is highly likely” that she will “accept that finding and direct verdict to the defendants”.

If the jury decides the lawsuit was filed on time, it must then determine whether OpenAI had a “charitable trust” and whether the company and its executives violated that trust.

The case comes as OpenAI moves towards a planned initial public offering that is expected to be among the largest ever.