The Trump family's World Liberty Financial crypto venture is being sued by one of its billionaire backers over allegations of extortion.

Justin Sun has accused World Liberty of an "illegal scheme" to seize his WLFI tokens, a cryptocurrency issued by the company.

Sun alleges the firm, co-founded by US President Donald Trump and his son Eric Trump, has "frozen" all of his tokens and stripped him of his right to vote on governance issues.

World Liberty has denied wrongdoing and accused Sun of "playing the victim while making baseless allegations to cover up his own misconduct".

Sun is an ardent supporter of Trump and his stance on cryptocurrencies, but accused "certain individuals" associated with World Liberty of acting against the president's values.

"They wrongfully froze all of my tokens, stripped me of my right to vote on governance proposals, and have threatened to permanently destroy my tokens by 'burning' them - all without any proper justification," he said in a social media post announcing the lawsuit.

Sun is the founder of a separate multi-billion-dollar crypto project, TRON. He initially invested $45m (£33m) in World Liberty and said that, at times, his WLFI tokens have been valued at more than $1bn.

Since September, the price of a single WLFI token has plunged from 31 cents to just under 8 cents.

Sun said his backing was driven by the Trump family's association with the project and his long-standing support for cryptocurrencies.

He also bought $100m worth of Trump's meme coins in July 2025.

But Sun alleged that those running World Liberty, including another co-founder, Chase Herro, are using it as a "golden opportunity to leverage the Trump brand to profit through fraud".

In his complaint, filed on Tuesday in a San Francisco federal court, Sun argued that initial promises to give token-holders the option to trade the currency in future "were false and misleading".

While the tokens at large became tradeable, Sun said World Liberty has blocked him from being able to sell a single one, and is now threatening to "burn" his - deleting them entirely.

Zach Witkoff, another co-founder of World Liberty and the son of President Trump's Middle East envoy Steve Witkoff, said Sun's lawsuit is a "desperate attempt to deflect attention from Sun's own misconduct".

"His claims are entirely meritless, and World Liberty looks forward to getting the case thrown out promptly," Witkoff said, and claimed that Sun has engaged in "misconduct that required World Liberty to take action to protect itself and its users".

Eric Trump added: "The only thing more ridiculous than this lawsuit is spending $6m on a banana duct-taped to a wall."

In 2024, Sun bought, then ate, an artwork by Maurizio Cattelan which consisted of a banana duct-taped to a wall.

Investors have also grown concerned about World Liberty borrowing against the value of its tokens.

Meanwhile, the Securities and Exchange Commission has dropped its investigation into Sun, with Senator Elizabeth Warren, a Democrat, questioning if it was tied to his investments in Trump's crypto ventures.

Sun had been accused of paying high-profile influencers to promote his companies on social media, without disclosing the payments.

Elsewhere, the Trump business behind his Truth Social platform replaced its chief executive Devin Nunes after a sharp fall in its share price.

Kevin McGurn, who has worked at Hulu, Vevo and T-Mobile, will temporarily take over from the former California congressman.

In the past year, shares in Trump Media & Technology have fallen in value by almost two thirds as it struggles to attract users beyond the US president, who frequently uses it to make announcements.