Elon Musk, the chief executive of Tesla Inc, was sued for defamation on Monday for falsely suggesting that a British caver who helped save 12 boys and their soccer coach from a Thailand cave in July was a pedophile and child rapist.

Vernon Unsworth sued over Musk's reference to him in a July 15 tweet as a "pedo guy," a comment for which Musk later apologized. The suit also claims that Musk called Unsworth a child rapist and sex trafficker in an Aug. 30 email to BuzzFeed News.

Tesla did not immediately respond to requests for comment from Musk and the company.

The lawsuit filed in the U.S. District Court in Los Angeles seeks at least $75,000 of compensatory damages, plus unspecified punitive damages.

The case adds to a slew of litigation against Musk, including over his running of Palo Alto, California-based Tesla, which the billionaire has said has caused him severe stress.

Tesla did not immediately respond to a request for comment.

Unsworth became a target for Musk after cave rescuers rejected Musk's offer of a mini-submarine created by his rocket company SpaceX to rescue the soccer team, which was finally freed after 18 days in the cave on July 10.

Though Unsworth told CNN three days later that Musk's offer was a "PR stunt" that had no chance of working and that Musk could "stick his submarine where it hurts," he said that did not justify Musk's use of Twitter and the media to defame him.

The July 15 tweet by Musk touted the mini-submarine and then, referring to Unsworth with a shorthand description of pedophile, said, "Sorry pedo guy, you really did ask for it."

Musk apologized on July 18, referring to Unsworth in saying "his actions against me do not justify my actions against him," and that "the fault is mine and mine alone."

But the complaint said that in the Aug. 30 email, Musk urged a BuzzFeed reporter to "stop defending child rapists," and then said Unsworth spent decades in Thailand until moving to Chiang Rai, "renowned for child sex-trafficking," to take a 12-year-old bride.

Unsworth said all of these accusations were false, and that the defamatory statements "were manufactured out of whole cloth by Musk out of a belief on his part that his wealth and stature allowed him to falsely accuse Mr. Unsworth with impunity" because he disagreed with him about the mini-submarine.

The case is Unsworth v Musk, U.S. District Court, Central District of California, No. 18-08048.