Elon Musk has renewed his attack on the British caver involved in last month’s rescue of a group of young Thai footballers, whom he had previously accused of being a paedophile.

In a series of tweets on Tuesday, the technology billionaire pointed out that Vernon Unsworth had not taken legal action against Mr Musk, and questioned why his earlier claims hadn’t been investigated.

Last month, Mr Musk referred to Mr Unsworth as “pedo guy” after the Briton, who lives in Thailand, criticised Mr Musk’s plan to use a mini submarine to rescue the 12 boys trapped in a Thai cave.

Mr Musk, who runs the electric car company Tesla and the space exploration group SpaceX, later apologised, saying his words were “spoken in anger”. However, he returned to the subject on Tuesday.

“You don’t think it’s strange he hasn’t sued me? He was offered free legal services,” Mr Musk tweeted after his comments last month were raised by Drew Olanoff, a tech communications executive. When questioned further he added: “Did you investigate at all? I’m guessing answer is no. Why?”