Last year, Vernon Unsworth, a cave explorer who advised on the rescue of kids trapped in a Thailand cave, got in a spat with Elon Musk. Musk labeled Unsworth a "pedo guy" in a tweet—and, in an ill-considered email to a reporter, later called him a "child rapist" who married a 12-year-old girl.

Unsworth sued Musk for defamation. Musk's legal response was that, while the accusations might not have been true, Musk believed they were true at the time he made them. The claim about marrying a 12-year-old (the woman in question says she was actually 33 when she met Unsworth) came from a private investigator to whom Musk paid $50,000 to dig into Unsworth's private life. Musk argued the high price tag was a sign that he was taking the issue seriously.

But now BuzzFeed is reporting that the private investigator Musk hired is a convicted felon and scammer.

"Public records and interviews reveal that the man Musk contracted, James Howard-Higgins, stole money from his business partners and was sentenced to three years in prison for fraud," reports BuzzFeed reporters Ryan Mac and Mark Di Stefano.

According to BuzzFeed, Howard-Higgins is "a 47-year-old man from Dorset in southwest England, who served 18 months of his three-year sentence in October 2016 for stealing more than £426,000 (about $525,000) from his company, Orchid Maritime Security Ltd."

A local media story in 2016 describes how a man named James Howard-Higgins defrauded his business partners and says he ultimately admitted to seven counts of fraud. BuzzFeed says this is the same man as the "James Howard" Musk hired to investigate Unsworth.

This might explain why a Musk PR representative declined to give me the private investigator's contact information when I asked for it last month.

Elon Musk's attorney didn't dispute BuzzFeed's findings in a Thursday email to Ars Technica.

"Mr. Musk refused to be shaken down over a tweet, so his team hired someone who approached them with information and they thought was a legitimate investigator," Musk lawyer Alex Spiro wrote. "Unbeknownst to them at the time, it now appears that he was engaged in his own fraud."

Howard-Higgins “sent an unsolicited email” to Musk

So how did Musk end up hiring an alleged convict for a sensitive job like this? Musk's lawyers explained how they found their private investigator in Musk's September response to the Unsworth lawsuit:

James Howard, a private investigator and head of the investigation firm Jupiter Military & Tactical Systems, sent an unsolicited email to Mr. Musk and offered to conduct an investigation of Mr. Unsworth... Mr. Howard explained that "Mr. Unsworth has skeletons in his cupboard." The following month, Mr. Musk, through the president of his home office, Jared Birchall, retained Mr. Howard to investigate.

A lot of the supposed dirt Howard gathered on Unsworth was little more than subjective hearsay. He reported that Unsworth was an "unpopular loner" and that other expatriates found him to be "creepy." At one point, Howard said he was trying to verify that Unsworth had moved to Pattaya Beach, a part of Thailand known for child sex trafficking. In his view, that would be evidence that Unsworth was a "sexpat." Howard didn't offer any hard evidence to back up these claims, and it's not clear if he ever actually spoke to sources in Thailand.

According to Musk's September legal filing, Howard told Birchall in an early phone call that Unsworth had married his wife when she was 12 years old. By the time he filed a written report, this had been revised to say she was around 18 years of age. Unsworth's partner, Woranan Ratrawiphukkunand, has since told reporters she was actually 33 at the time she met Unsworth.

Unsworth's lawyer blasted Musk's behavior in a statement to BuzzFeed. "Musk had no credible or verified information at any time that supported his false accusations that Mr. Unsworth was a pedophile, a child rapist who married a 12-year old child bride, or lived for 30 years in Pattaya Beach."