The supervisory authority of the American markets is suing Elon Musk for the disclosure of the participation of Twitter

The US markets watchdog has filed a lawsuit against Elon Musk accusing him of failing to disclose that he had accumulated a stake in Twitter, which allowed him to buy shares at “artificially low prices.”

The Securities and Exchange Commission (SEC) lawsuit says the billionaire Tesla boss saved $150m (£123m) in share buybacks as a result.

According to SEC rules, investors whose holdings exceed 5% have 10 days to announce that they have exceeded that limit. Musk did so 21 days after the purchase, the filing says.

In a social media postMusk called the SEC a “totally broken organization.”

He also accused the regulator of wasting its time when “there are so many actual crimes that remain unpunished”.

“Musk’s breach resulted in substantial economic harm to investors,” the SEC complaint said.

In a statement emailed to BBC News, Musk’s lawyer, Alex Spiro, described the lawsuit as a “farce” and “a campaign of harassment” against his client.

Twitter’s stock price rose more than 27% after Musk made his share purchase public on April 4, 2022, the SEC said.

Musk ended up buying Twitter for $44 billion in October 2022 and has since changed the name of the platform to X.

The complaint was filed by the SEC in a federal court in Washington DC on tuesday

The lawsuit also asked the court to order Musk to give up the “unfair” profits and pay a fine.

SEC chief Gary Gensler announced in November that he would step down from his role when Donald Trump returns to the White House on January 20.

That was after Trump said he planned to fire Mr. Gensler on “day one” of his new administration.

Under Mr. Gensler’s leadership, the SEC is meeting with Musk, who is a close ally of the president-elect.

But Musk had conflicts with the SEC long before Mr. Gensler took over.

In 2018, the regulator accused Musk of defrauding investors by saying he had “secured financing” to take Tesla, the electric car company he runs, private.

He later settled the charges, resigning as chairman of the company’s board and agreeing to accept what was called a Twitter sitter – limits on what he could write on social media about the company.