A British caver who helped rescue 12 boys from a Thai cave has said he may take legal action against Elon Musk after the billionaire entrepreneur called him a "pedo".
Mr Musk launched the extraordinary tirade against Vernon Unsworth without providing any justification or explanation, after the cave expert dismissed his offer of a miniature submarine to extract the youth footballers from the Tham Luang cave as a "PR stunt".
The Wild Boar team and their coach were rescued last week by an international team of divers through a narrow network of twisting, flooded tunnels.
Mr Unsworth, who provided mapping knowledge of the cave to rescuers, said Mr Musk's prototype would have had "absolutely no chance of working".
Mr Musk, head of the electric-vehicle maker Tesla, responded on Sunday in a bizarre series of tweets referring to Mr Unsworth as "pedo guy" without using his name. "Pedo" is short for paedophile.
He then reasserted the claim, tweeting from his official account to more than 22 million followers: "Bet ya a signed dollar it's true".
Mr Musk later deleted the tweets and did not immediately respond to a request for comment through Tesla.
Mr Unsworth said on Monday that he had not reviewed the tweets in full and had only heard about them.
Asked if he would take legal action against Mr Musk over the allegation, he said: "If it's what I think it is, yes."
Mr Unsworth said he would make a decision after returning to the UK this week, but said the episode with Mr Musk "ain't finished".
"He's just a PR stunt merchant – that's all he is," he said.
Mr Unsworth, who lives part of the year in Thailand, took part in the massive 18-day effort to rescue the 12 boys and their coach, a mission that ended on July 10 when the last five members were extracted.
The boys got stuck in the cave after wandering in on June 23 after football practice only to find themselves trapped by rising floodwaters.
They were found nine days later on a muddy embankment several kilometres inside.
The unprecedented operation to haul them out involved sedating the footballers and swimming and carrying them through tight, waterlogged passages.
The boys are all in good health and expected to be released from the hospital on Thursday.
Mr Musk's tweets prompted condemnation from those who took part in the mission to save the boys.
Claus Rasmussen, a Danish national and instructor at Blue Label diving in Phuket, called the allegations "inappropriate" and praised Mr Unsworth's role in the rescue.
"He was the guy who effectively mapped most of that cave," he said. "He was one of the driving forces in getting everything done and clarifying for us divers what was going on."
Mr Musk had earlier provoked condemnation after tweeting that the Thai rescue chief, who had declined the submarine prototype offer, was not really in charge of the operation.