File this under “Juicy!” Fox News contributor and private investigator Bo Dietl leaked damaging information about Rupert Murdoch’s then-wife, Wendi Deng Murdoch, to Gawker. Who hired him to do so is still a mystery.

On Friday, Gawker’s Editor-in-Chief, John Cook, wrote about a pseudonymous email he received in 2008 with a Microsoft Word attachment:

The Word document began: “What media mogul billionaire’s wife has been guilty of so many sexual escapades that she is the talk of LA?” It went on to claim that Wendi Deng, the then-wife of Rupert Murdoch, was a “vicious...hustler,” “licentious...whore,” and “nymphomaniac” whose whose “path to [Murdoch’s] board room and bed room is paved with betrayal, infidelity, adultery and continuous scandalous affairs.” While it didn’t directly name any men Deng was alleged to be carrying on with, the document said “the mogul’s wife is having an affair with an executive from the media moguls own company.”

At the time, rumors were swirling in New York media circles about Deng's alleged infidelities, specifically about a purported relationship with MySpace co-founder Chris DeWolfe, whose company Murdoch had bought in 2005 in a $580 million deal that turned out to be as catastrophically ill-considered as his marriage to Deng.

Recently, post-Murdoch divorce, Cook revisited the document. Now, he was able to trace it back to Bo Dietl - a retired New York City policeman, a current private investigator, Fox News contributor and personal friend of Fox News chief Roger Ailes. However, Dietl has also worked for Bill O’Reilly to help smear Andrea Mackris, the woman who accused him of sexual harassment.

In his New York Magazine post on the subject, Ailes biographer Gabriel Sherman outlines the “well-known tensions” that existed between Ailes and Deng. Sherman describes Ailes as “a beneficiary” of Murdoch’s subsequent divorce and adds, “a close Murdoch associate told me that Ailes and Murdoch had rekindled their friendship now that Wendi was out of the picture.”

However, Dietl has expressly denied being hired by Ailes to malign Deng. Cook writes that after initially suggesting a rogue employee was the tipster, Dietl later admitted otherwise:

Dietl confirmed that he had, indeed, been hired to spread dirt on Deng. He wouldn’t say who it was, but he did say who it wasn’t.

“It was not Roger Ailes who hired me to look into Wendi and Rupert,” he told me.

The lingering question in my mind is not just who hired Dietl, but who else may have been targeted by Fox for a secret smear campaign.