Elon Musk has said his deal to buy Twitter “cannot move forward” until he sees “proof” of the site’s estimate that spam and fake accounts make up less than 5% of users.

The billionaire Tesla boss has publicly sparred with the social media firm’s chief executive over the number of bot accounts on the platform and said he believes they are higher than Twitter’s figures indicate.

Mr Musk tweeted last week that his £34.5 billion deal to acquire the site was “on hold” while he sought more details about the number of fake accounts on the site.

Twitter chief executive Parag Agrawal defended the company’s approach to estimating the scale of spam accounts on Twitter – to which Mr Musk responded with a poo emoji and repeated his claim that the 5% figure was an underestimation.

“20% fake/spam accounts, while 4 times what Twitter claims, could be *much* higher,” Mr Musk tweeted on Tuesday morning.

“My offer was based on Twitter’s SEC filings being accurate.

“Yesterday, Twitter’s CEO publicly refused to show proof of 5%.

“This deal cannot move forward until he does.”

Some experts have suggested the billionaire may be looking for ways to try and renegotiate the price of the deal or find a way to walk away from it.

Twitter’s share price remains well below the $54.20 Musk has agreed to pay per share to complete the deal.

According to a report by Bloomberg, Mr Musk told a conference in Miami on Monday that renegotiating a deal for the company at a lower price was not “out of the question”.

Nicky Danino, principal lecturer in computer science at the University of Central Lancashire, said: “Although things are stalling, I’d be surprised if Musk is trying to get out of the deal completely. This may be a negotiation tactic.

“I say this because buying Twitter would greatly increase Musk’s power.

“In a world where information is one of our most precious commodities, investing in a platform with such a vast bank of knowledge on the human population is a sound business move.”

But social media expert and industry commentator Matt Navarra said he thought Mr Musk could be willing to pay a one billion dollar “breakup fee” included in the deal in order to walk away.

“Elon’s latest Twitter deal antics should surprise no-one. There are so many reasons why backing out of the deal would be the smartest move for him right now,” he said.

“Forfeiting $1 billion to walk away would be far cheaper than the escalating costs of this deal due to Twitter’s plunging share price and the hammering Tesla’s stock is taking. Twitter is in a very vulnerable position right now, and Elon Musk knows it.

“The tech drama is far from over, the finale is still to come.”

It has been suggested that the Tesla and SpaceX boss’ concern over the number of fake accounts on the site is linked to his plans to try and monetise Twitter’s user base through more advertising and subscriptions.

Susannah Streeter, senior investment and markets analyst at Hargreaves Lansdown, said these figures are a “key metric” in “establishing an accurate number of real tweeters is considered to be key to future revenue streams”.

On announcing the deal last month, Mr Musk said he wanted “defeat the spam bots” and bolster free speech on the platform.

He also said he wanted to “unlock” the potential of the site and “make Twitter better than ever by enhancing the product with new features”.