The suit was filed in the U.S. District Court in Los Angeles, more than two months after Elon Musk referred to the plaintiff as a "pedo guy."
Tesla CEO Elon Musk was sued on Monday for defamation for allegedly suggesting that one of the rescuers of 12 boys and their soccer coach from a Thailand cave in July was a pedophile.
Vernon Unsworth, a British caver, filed his lawsuit in the U.S. District Court in Los Angeles, more than two months after Musk referred to him as a "pedo guy" in a July 15 tweet.
Tesla did not immediately respond to a request for comment from Musk and the company.
Unsworth had called Musk's offer to build a "tube" to help rescue the children a "PR stunt," and said Musk manufactured the pedophile allegation "out of whole cloth" simply because he disagreed with that assessment.
"Despite his total lack of information supporting his false and defamatory accusations, Musk overtly conveyed to the world that he was in possession of undisclosed false and defamatory facts proving Mr. Unsworth to be guilty of the accusations," the complaint said.
The lawsuit seeks at least $75,000 of compensatory damages, plus unspecified punitive damages.
Musk apologized for his tweet on July 18, saying "his actions against me do not justify my actions against him," and that "the fault is mine and mine alone."
Tesla shares fell a fraction of a point to close at $294.84 on Wall Street.