Elon Musk

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.

Controversy grew on Wednesday over tweets from Elon Musk engaging with criticism of Twitter employees, despite a promise from the entrepreneur not to “disparage” the company or its representatives while he completes the deal to acquire the social media platform.

The Tesla chief executive and world’s richest person revealed in a regulatory filing on Thursday that he had launched a hostile takeover of Twitter. He further confirmed the move in a public appearance at the TED conference in Vancouver later that day.

That’s the contention of Michael Burry — the investor made famous in “The Big Short” for his financial crisis housing bets. In a now-deleted tweet, he suggested Musk is selling Tesla shares to cash out of his position as the stock plummets

It comes days after he asked his 63 million Twitter followers whether he should sell 10% of his stake in Tesla.

The company's shares fell by around 16% in the two days after the poll came out in favour of him selling shares, before regaining some ground on Wednesday.

Tesla is the world's most valuable carmaker, with a stock market valuation of more than $1tn.

Mr Musk sold more than 930,000 shares in the company, about 0.5% of his stake, according to filings with the US stock market regulator.

The Tesla and SpaceX entrepreneur was pushed into the top slot after Tesla's share price increased on Thursday.

He takes the top spot from Amazon founder Jeff Bezos, who had held it since 2017.

Musk's electric car company Tesla has surged in value this year, and hit a market value of $700bn (NZ$964bn) for the first time on Wednesday.

That makes the car company worth more than Toyota, Volkswagen, Hyundai, GM and Ford combined.

Musk reacted to the news in signature style, replying to a Twitter user sharing the news with the remark "how strange".

The entrepreneur made the pledge as he announced an improved microchip for its driverless vehicles.

Mr Musk told investors he expected regulators to approve ride-hailing in some areas for autonomous vehicles.

He added: "I feel very confident in predicting autonomous robotaxis next year."

Mr Musk said he expected the scheme to operate on a model similar to that of Uber or Airbnb.

The company unveiled computer hardware for what it said was "full self-driving" capabilities in the form of the new microchip.

During a speech at a TED Talks conference, Musk -- the Tesla (TSLA) and SpaceX CEO -- unveiled what he hopes to accomplish with his latest venture, The Boring Company.

I’ve written at length about President Trump’s relationship with the technology heartland.

On the one side, you have the likes of Paypal founder and major investor Peter Thiel, who is now very much part of Trump’s inner circle.

On the other, you have tech bigwigs like Apple’s Tim Cook and Alphabet’s Larry Page, who were cooperative but mostly quiet when honouring the then President-Elect’s invite to meet him at Trump Tower last year.

The company's founder and chief executive, Elon Musk, said Monday that these struts had flown many times before without any problem. But two minutes into the June 28 launch, one of the struts in the second stage of the unmanned Falcon 9 rocket likely broke loose. The strut was holding down a helium bottle in the liquid oxygen tank.

Musk says if the strut snapped as engineers believe, the helium bottle would have shot to the top of the tank at high speed, dooming the rocket and its Dragon supply ship for the International Space Station.