The case took a new twist this month after court documents showed that Musk, after his initial tweets in July of last year, had hired a private investigator to dig up dirt about Unsworth. It turned out the detective was a convicted conman.

Musk then sent an "off-the-record" email to a BuzzFeed reporter in which he said Unsworth had married a 12-year-old child bride in Thailand. Unsworth says that's not what the investigator told Musk.

Unsworth said in court filings that he met his Thai wife in London when she was 32 years old. The caver also scoffed at Musk's defence that he didn't intend for his off-the-record email to be published.

"Musk contends that the republication of his email accusations was not reasonably foreseeable despite the undisputed facts that he emailed them to a reporter with whom he had no historical relationship," Unsworth said.