The British diving expert, who Tesla and SpaceX CEO Elon Musk called a “pedo guy” in a public attack on Twitter, is striking back.

Vernon Unsworth filed a lawsuit Monday in the U.S. District Court for the Central District of California against Musk for defamation. The lawsuit alleges that between July 15 and August 30, Musk periodically used Twitter and emails to the media to publish false and defamatory accusations against Unsworth, including accusations of pedophilia and child rape.

The lawsuit is seeking compensatory damages of at least $75,000 and punitive damages in “an amount shown to be reasonable and just under the evidence to punish Musk and deter him from repeating such conduct.”

Unsworth was one of many people directly involved in the efforts to extract 12 boys and their soccer coach from the Tham Luang Nang Non cave system located in Northern Thailand after flooding trapped the group for weeks. The rescue effort drew global media coverage, even attracting Musk, who got involved by sending a mini submarine built out of rocket parts that he thought could help.

The initial “pedo guy” attack came after Unsworth gave a critical interview to the media saying Musk’s mini sub “had absolutely no chance of working.” The diving expert ended an interview segment by suggesting Musk should “stick his submarine where it hurts.”

Musk lashed out on Twitter and insinuated that Unsworth was a pedophile. He later deleted the offending tweet and tried to backpedal — even offering an apology of sorts on Twitter. And it could have all ended there. But then Musk dug it all up again during a debate with ex-TechCrunch journalist Drew Olanoff — once again on Twitter. Olanoff had brought up the “pedo guy” attack as an example of Musk telling untruths.

You don’t think it’s strange he hasn’t sued me? He was offered free legal services. And you call yourself @yoda … — Elon Musk (@elonmusk) August 28, 2018

Musk then took it further and exchanged a series of emails with BuzzFeed about Unsworth.

In light of some questions about my email correspondence with Elon Musk, I'm going to share all my emails with him that pertain to the reporting of our latest story. I first emailed him on Aug. 29 after learning that he was the subject of a legal threat. pic.twitter.com/c1kkBVMuqm — Ryan Mac (@RMac18) September 5, 2018

A Tesla spokesperson could not be immediately reached for comment. A request for comment was sent to Musk via email. If he responds, the story will be updated.

Unsworth v Musk by TechCrunch on Scribd