DES MOINES, Iowa — Corey Lewandowski, the campaign manager for 2016 GOP frontrunner Donald Trump, exposed a blatant conflict of interest on Wednesday that the Fox News Channel has been hiding for months.

Lewandowski showed how Fox News has been hiding the fact that Fox News Channel Vice President Bill Sammon has a daughter working for the campaign of the Washington establishment-backed Sen. Marco Rubio (R-FL).

Sammon’s daughter, Brooke Sammon, is Rubio’s national press secretary, and obviously both have a vested interest in the success of the Rubio campaign and the demise of the other campaigns.

CNN’s Erin Burnett asked Lewandowski about Fox News’s controversial anti-Trump statement from Tuesday evening—and specifically the network’s claim that the top Trump aide had allegedly made threats against Fox News anchor and Thursday debate co-moderator Megyn Kelly—when he responded by dropping the explosive revelation.

Lewandowski revealed two things for the first time: that the executive he was discussing matters with was Bill Sammon, and that Sammon’s daughter Brooke Sammon works for Rubio’s campaign, giving the first-term Floridian Senator an obvious boost. That blatant conflict of interest has never before been disclosed to the viewers of Fox News by the network.

“Not only did I not make threats, but the conversation with the Fox News executive—his daughter works for the Rubio campaign, he’s one of the executives on Fox that writes the debate questions so maybe he has his own ulterior motives, I’m not sure,” Lewandowski told Burnett in the Wednesday evening CNN interview. He went on:

But his daughter is a senior executive on the Rubio campaign, maybe he should disclose that before he’s writing the debate questions for Fox. There were no threats made. The bottom line is this isn’t about me and it’s not about Megyn Kelly. It’s about the way that Fox News put out a statement about Mr. Trump that’s wholly inaccurate and unfair and it’s very difficult to treat someone fairly when they’re the GOP frontrunner when you put out a statement like that.

When Burnett followed up, Lewandowski doubled down. “What I said was the Fox News executive who oversees the debate process, their daughter is a senior executive on the Marco Rubio campaign—is what I said,” the Trump campaign manager said.

A Fox News spokesperson has not responded to Breitbart News’s requests for comment throughout the day on Wednesday. A Rubio spokesman, communications director Alex Conant, responded to a Breitbart News inquiry on this matter by standing up for Brooke Sammon and questioning Breitbart News’s integrity.

“It’s no secret Breitbart traffics in conspiracy theories, but this accusation is a whole new level of crazy,” Conant said in an email. “Brooke is a star of our campaign and her integrity and professionalism is second to none. If you’re worried about someone’s integrity, you should do some serious self examination.”

Conant has not answered a pair of follow-up questions. One question Conant won’t answer centers specifically on whether Brooke Sammon has ever in any way communicated with her father about the Rubio campaign–including regarding debate matters. The other question Conant won’t answer is why, if “Breitbart traffics in conspiracy theories,” Sen. Rubio’s campaign provides Breitbart News with exclusives like the one earlier on Wednesday about his new ad targeting Evangelical voters.

“I believe you can’t have a strong America without strong families. I believe in the fundamental freedoms that make us great. And I believe in God; that God has blessed America,” Sen. Rubio says in a new advertisement he provided exclusively to Breitbart News, for instance. Conant and his team provided Breitbart News with that exclusive mere hours before changing their tune on Breitbart News.

Bill Sammon is a Fox News Channel Vice President and the bureau chief of that network’s Washington, D.C. team. Several times leading up to the previous Megyn Kelly-co-moderated debate back in August 2015, it was confirmed that Sammon was personally involved in crafting the entire focus of the debate.

For instance, on Howard Kurtz’s Aug. 2 Media Buzz show on the Fox News Channel, Kurtz and Fox’s Chris Stirewalt confirmed that Sammon is the “secret weapon” crafting the questions.

“You’ve been to this rodeo before,” Kurtz asked Stirewalt. “How do you and Megyn Kelly and Bret Baier and Chris Wallace go about formulating your questions, knowing the candidates are going to try to pivot to their talking points?”

“Well, the first thing is we have a secret weapon and that is Bill Sammon, who is the best at not only team cohesion and keeping everybody on point about what the point is, but in crafting the questions,” Stirewalt replied before Kurtz interjected that Sammon is the Fox News Channel’s “Washington bureau chief.”

“Absolutely, he’s a managing editor and a great mind and a great journalist and so that is a big help,” Stirewalt finished.

In addition, a Washington Post pre-debate profile of Fox News Sunday host Chris Wallace—one of the other debate moderators alongside Megyn Kelly and Bret Baier—confirmed Sammon’s involvement in crafting the narrative of the debate. Of course, that profile quotes Wallace as saying he has several “doozies” prepared for GOP frontrunner Donald Trump.

“On a recent Thursday morning, Wallace walked the few steps from his small, memorabilia-filled office — his father’s Rolodex, a photo of him playing hoops with Michael Jordan — to the more spacious suite of his boss, Bill Sammon, the vice president of news, who had called together a small debate-prep meeting,” the Post’s Krissah Thompson wrote.

Thompson then detailed what the debate-prep room was like one day when Wallace and Sammon prepared for battle, quoting the two of them extensively—and making clear that Sammon was in charge.

What’s interesting, however, is that these people, who claim to be journalists—Wallace, Baier, Kelly, Stirewalt, Kurtz, and pretty much everyone else at the Fox News Channel, especially Sammon—all committed what is pretty much a cardinal sin in journalism: They didn’t disclose a major conflict of interest ahead of a presidential debate. That conflict, of course, is that Brooke Sammon—Rubio’s national press secretary—is the daughter of Fox News executive Bill Sammon.

Brooke Sammon is no small player in Rubio’s orbit, either. She’s second in command to Rubio communications chief Alex Conant, and has worked for the senator for years.

The network did not disclose this conflict of interest to anyone–most importantly, the 24 million people who watched that first debate this summer. It’s unclear why the network has hidden this detail. Other GOP presidential campaigns have been whispering about pro-Rubio bias at Fox, but none have been willing to publicly hammer the network, except for Trump.

Lewandowski has gotten close to exposing this conflict of interest before—making an allusion to it on Good Morning America on Wednesday morning—but not until his CNN appearance was he so explicit.

“It’s a shame, when you have a conversation with some of the Fox executives, you’d hope they’d keep that conversation private,” Lewandowski said on GMA. “Instead you have executives over there who have relatives working for other campaigns. These are the people who are putting debate questions together.”