Elon Musk

From November 2021 to December 2022 he lost around $US165 billion ($NZ259b), Guinness World Records said in a blog on its website.

BBC reports the figures are based on data from publisher Forbes, but Guinness said other sources suggested Musk's losses could have been higher.

It follows a fall in value of shares in Musk's electric car firm Tesla after he bought Twitter last year.

His $US44b takeover of the social media company has sparked concerns among investors that Musk is no longer giving Tesla enough attention.

A US securities filing showed he unloaded 22m shares in the world's most valuable carmaker over three days from Monday to Wednesday.

The sale was the second big chunk of stock he cashed out since his $44b purchase of Twitter in October.

It was not clear if the sales were related to the Twitter acquisition, but they were annoying investors upset by a perception he was diverting his focus and resources to Twitter ahead of Tesla.

Mr Musk walked away from his $44bn (£36bn) bid to buy Twitter earlier in July, prompting the company to sue him.

Twitter hopes that the court will order Mr Musk to complete the takeover at the agreed price of $54.20 per share.

The tech billionaire has accused Twitter of withholding information about fake accounts.

His legal team has called for the trial to be held early next year due to its complexities, but Twitter asked for a September date.

Twitter chairman Bret Taylor said on the micro-blogging platform that the board planned to pursue legal action to enforce the merger agreement.

"The Twitter Board is committed to closing the transaction on the price and terms agreed upon with Mr Musk...," he wrote.

In a filing, Musk's lawyers said Twitter had failed or refused to respond to multiple requests for information on fake or spam accounts on the platform, which is fundamental to the company's business performance.

The meeting is scheduled for Thursday, and Musk will take questions directly from Twitter employees, the source added.

The news, first reported by Business Insider, comes after Twitter said last week that it anticipated a shareholder vote on the sale by early August.

A Twitter spokesperson confirmed that Musk would attend the company all-hands meeting this week.

Ever since Musk's takeover bid, many Twitter employees have expressed concerns that the billionaire's erratic behavior could destabilize the social media company's business, and hurt it financially.

In a letter filed with regulators, Mr Musk said he was entitled to do his own measurement of spam accounts.

The letter formalises a dispute that has simmered for weeks after Mr Musk declared the deal "on hold" pending further information.

Twitter has defended its estimates.

But Mr Musk has said he believes spam and fake accounts represent a far greater share than the less than 5% of daily users that Twitter reports publicly.

The new policy was shared in emails that were leaked to social media.

Tesla did not respond to a request for comment on the messages, one of which appeared to be addressed to executives.

People who are unwilling to abide by the new rules can "pretend to work somewhere else" Mr Musk said on Twitter, when asked about the policy.

"Everyone at Tesla is required to spend a minimum of 40 hours in the office per week," he wrote in one of the emails. "If you don't show up, we will assume you have resigned."

Mr Musk tweeted that the deal "cannot move forward" unless Twitter backs up its claims that less than 5% of daily users are fake or spam accounts.

Twitter has defended its figures, adding that Mr Musk waived rights to "due diligence" to clinch the deal.

The spat has raised doubts about the takeover.

Analysts have speculated that Mr Musk may be looking for ways to renegotiate the price of the deal or walk away.

The richest man in the world agreed a $NZ70 billion takeover bid with the Twitter board last month.

But he said it was not a done deal and that ideally it would be completed in the next two to three months.

Twitter's decision to ban the former US president was "morally wrong and flat-out stupid", Musk told the Financial Times Future of the Car summit.

In January 2021, Twitter said Trump's account was "permanently suspended ... due to the risk of further incitement of violence" following the storming of the Capitol.

Musk, who made the shock bid less than two weeks ago, has claimed he is the right person to "unlock" the social media firm's "extraordinary potential".

He has suggested a series of changes from relaxing its content restrictions to eradicating fake accounts.

The firm initially rebuffed Musk's bid, but it will now ask shareholders to vote to approve the deal.