Tesla boss Elon Musk appears to have doubled down on his claim that a British explorer who was instrumental in freeing a group of Thai boys trapped in a cave is a “pedo”.

The Tesla chairman was widely criticised last month for making the unfounded allegation against Vernon Unsworth, who was part of an international team that freed the young footballers and their adult coach from the Tham Luang cave complex in northern Thailand.

Mr Unsworth had criticised a mini-submarine that Musk had delivered for the rescue as impractical and said he could “stick [it] where it hurts”.

Mr Musk responded by calling Mr Unsworth a “pedo guy”, later tweeting: “Bet ya a signed dollar it’s true.” He deleted both tweets soon after.

He has never presented any evidence for the allegation nor claimed to have any. He apologised for the remark last month after Mr Unsworth threatened to sue, Tesla shares dived, and the company’s investors issued an open letter demanding Mr Musk apologise.

Mr Musk was responding to another critic on Twitter on Tuesday night when he appeared to reaffirm the accusation. “You don’t think it’s strange [Unsworth] hasn’t sued me? He was offered free legal services,” he wrote.

Under pressure

“Did you investigate at all? I’m guessing answer is no. Why?” he wrote in subsequent tweets that are still online.

Mr Musk has been under pressure from Tesla investors over his erratic behaviour on social media and record losses posted by the electric vehicle manufacturer.

His latest comments saw the shares dip another 2.2 per cent.

Mr Musk told the New York Times this month the past year had been “excruciating” and the “most difficult and painful of my career”, claiming he had been working up to 120 hours a week and neglecting his health and family.

He is also being sued by investors for tweeting earlier this month his intentions to take his publicly traded company private, with the assurance: “Funding secured.”

The tweet caused Tesla’s share price to surge 11 per cent, hurting the short-selling investors whose return depends on the company losing value.

Lawyers have warned the tweet may have broken a law that bans public companies from announcing plans to buy or sell securities if executives do not intend or do not have the means to complete the deal, or if they are trying to manipulate the stock price. – Guardian Service