A British diver who helped rescue youth football players trapped in a cave in Thailand is suing Elon Musk, claiming the Tesla chief falsely accused him on Twitter of being a paedophile.
The lawsuit filed by Vernon Unsworth in Los Angeles federal court seeks more than £57,000 in damages and a court order stopping Mr Musk from making further allegations.
Mr Unsworth, a caving expert, provided advice and experience which were considered crucial to the rescue operation of the 12 young footballers and their coach.
Mr Unsworth had criticised a well-publicised effort by Mr Musk to lend a custom-built mini-submarine to the rescue effort as “showboating” in a television interview.
The Tesla boss and SpaceX engineers had built a small submarine and shipped it to Thailand to help with the rescue, but the device was not used, and Mr Unsworth branded it a “PR stunt”.
In retaliation, Mr Musk called the Brit "pedo [sic] guy" in a tweet to his 22.5 million followers which has since been deleted.
Mr Unsworth and his legal team deny the allegations made by Mr Musk.
Mr Musk later accused Mr Unsworth of moving to Thailand to be with a bride who was around 12.
The lawsuit alleges that Mr Musk, apparently angered by Mr Unsworth's remarks, began a campaign to destroy his reputation "by publishing false and heinous accusations of criminality against him to the public".
In a series of tweets on July 15, Mr Musk, who personally delivered the submarine to the cave, wrote that he never saw Mr Unsworth and challenged him to show a video of the final rescue.
"Sorry pedo guy, you really did ask for it," he tweeted.
Later on Twitter, Mr Musk wrote: "Bet ya a dollar it's true."
He later deleted the tweets and apologised after being criticised by shareholders, the lawsuit alleges, stating in a tweet that his words were "spoken in anger" and that the sub was built out of kindness according to specifications from the dive team leader.
But on August 28, Mr Musk tweeted again, writing: "You don't think it's strange he hasn't sued me? He was offered free legal services."
The lawsuit says that with the tweet, Mr Musk sought to tell the average reader that Mr Unsworth's failure to sue at the time was evidence that he was a paedophile.
Two days after the August 28 tweet, Mr Musk emailed a BuzzFeed News reporter, suggesting the reporter investigate Mr Unsworth and "stop defending child rapists", according to the lawsuit, which runs to 65 pages including exhibits.
"He's an old, single white guy from England who's been travelling or living in Thailand for 30 to 40 years," Mr Musk wrote, adding that Mr Unsworth moved to Thailand "for a child bride who was about 12 years old at the time", according to the lawsuit.
Then in a second email to BuzzFeed, he accused Mr Unsworth of being a liar and said he was not on the cave dive team.
Mr Unsworth and his legal team have denied the allegations made by Mr Musk: "Mr Unsworth is not a paedophile.
"Mr Unsworth has never engaged in an act of paedophilia.
"Mr Unsworth is not a child rapist," the lawsuit said, adding that Mr Unsworth has never been married to a minor.
He has a "significant other" in Thailand, a 40-year-old woman with whom he shares a house, according to the lawsuit.
He started going to Thailand in 2011, where he explored and mapped caves, the documents add.
The lawsuit also explains Mr Unsworth's role in the rescue, saying that on June 23, when the youngsters became trapped, several Thai officials called and asked him to go to the cave as soon as possible.
He was the first foreign rescuer to arrive.
He recommended that the Thai Government seek help from divers in the UK, and called friend and fellow diver Rob Harper.
Mr Harper, who had just returned from exploring Thai caves with Mr Unsworth, took two other divers, John Volanthen and Rick Stanton, to help with the rescue.
The boys, aged between 11 and 16, were reached on July 2 by Mr Volanthen and Mr Stanton.
"Together with Mr Unsworth, Mr Harper, Mr Volanthen, and Mr Stanton put together the dive portion of the rescue plan that ultimately saved the boys," the lawsuit said.
It conceded that Mr Unsworth was not involved in the final planning stages of the rescue because he did not have enough experience to make the dive.
The matter was revived last week, when Mr Musk – when asked about the threat of libel action – continued with his accusations.
Mr Musk has provided no evidence for his allegations.