The war between Gawker and Fox News just got a little uglier.

After months of digging up dirt on Roger Ailes, the chairman and CEO of the top-rated cable news network, Gawker sleuth John Cook has unearthed some potentially damaging dish on Fox News primetime stalwart Bill O'Reilly.

In Cook's latest investigative report, he writes: "Last summer, Fox News anchor Bill O'Reilly came to believe that his wife was romantically involved with another man. Not just any man, but a police detective in the Long Island community they call home. So O'Reilly did what any concerned husband would do: He pulled strings to get the police department's internal affairs unit to investigate one of their own for messing with the wrong man's lady."

The piece is sourced to "someone who has a longstanding personal relationship with [the detective who was allegedly tapped to probe his fellow officer], and who heard the account directly from [that detective] himself. The source provided contemporaneous e-mail traffic to support his account."

All the relevant parties were contacted for comment, including Fox News, which fired back with a vigorous dismissal of Cook's story. (Disclosure: Cook used to be a reporter at Yahoo!, where he worked with the team that produces the blog you are now reading.)

"Gawker has been lying about Fox News for several years," a Fox News spokesperson told Adweek. "We are not going to dignify this with any further comment."

Last week, the Fox News show "Fox & Friends," as well as the channel's website, ran stories claiming Gawker's traffic has recently dropped 75 percent, a claim Gawker refuted while also suggesting that the negative press was a pre-emptive strike against a story Cook was working on, which turned out to be today's O'Reilly expose.

According to Adweek, "the network denies that it was attempting to preempt Cook's story by dumping on Gawker, saying that there was no link, that the decision to report on Gawker's traffic figures was purely editorial, and that producers at 'Fox & Friends' wouldn't have had knowledge of the impending O'Reilly story."

But this is hardly the first time Cook's reporting has rankled Fox News suits. He's repeatedly pursued titillating scoops about Ailes, such as a report that Ailes was caught spying on one of the reporters from the local newspaper that he and his wife run out of the bucolic Hudson Valley hamlet where they nest.

It's also hardly the first time Fox News has lashed out at the influential news and gossip website--Gawker compiled a montage of such clips after publishing the O'Reilly story today.