The hedge fund mogul, Bill Ackman, is urging the chief executive of Disney, Bob Iger, to launch an investigation into a bombshell affidavit, purportedly from a whistleblower inside ABC News, which claims that the network colluded with the Harris campaign to disadvantage President Trump during the debate.

The affidavit is the latest blow to ABC News, which is facing a firestorm of criticism over its handling of last week’s presidential debate. During the debate, moderators David Muir and Linsey Davis aggressively fact checked Trump while not correcting Vice President Harris once, repeatedly steered the debate to topics of strength for Ms. Harris, such as abortion, and pressed Trump about the events of January 6.

Screenshots of the affidavit, which is dated September 9, the day before the debate, surfaced on social media this weekend, prompting a whole new barrage of attacks against the left-leaning media outlet, ABC News, which is part of the Disney ABC Television Networks unit of The Walt Disney Company.

The document, which has not yet been verified, was initially posted by a pro-Trump account on X called “Black Insurrectionist.” The user announced on September 12, two days after the debate, that they had signed a non-disclosure agreement with the attorney for the ABC whistleblower and would be releasing screenshots of some pages of the affidavit, which they did three days later. In response to claims that the documents were fake, the account promised to file “for all to see” the affidavit as well as a lawsuit against ABC for election interference. The user did not specify whether a suit had been filed yet, but wrote: “See you in court soon @ABC.”

Its author — who claims to have worked in various “technical and administrative positions” at ABC News over the past ten years — writes that they had borne witness to the network’s shift “from unbiased reporting to a model influenced by external factors.” The affidavit, the whistleblower notes, is meant to “document and provide transparency regarding the issues of fairness and impartiality in the debate process and broader concerns about journalistic integrity at ABC News.”

The unverified affidavit, most of which has yet to be released, alleges that the Harris campaign negotiated with the network to secure a slew of advantages both ahead of and during the debate, including receiving a list of sample questions beforehand; and barring the monitors from asking questions related to President Biden’s health, Ms. Harris’s tenure as Attorney General at San Francisco, and the tenure of Ms. Harris’s brother-in-law, Tony West, at the Justice Department, where he handled sensitive financial issues with big banks following the financial crisis of the mid-aughts.

The “whistleblower” also claims that the vice president arranged with ABC News for accommodations to make her appear more visually favorable throughout the debate, including receiving a smaller podium than Trump — who is nearly an entire foot taller than her — and ensuring that her split-screen television views were “favorable” to Trump’s.

The allegations were signed and notarized in the affidavit before the debate, and a certified letter was sent to speaker of the House, Mike Johnson, dated September 9. The purported ABC News employee also claims to have secret video recordings to corroborate his or her accusations. Mr. Johnson has not confirmed receipt of the letter nor has he responded to the Sun’s request for comment.

“I find the allegations credible as written and also because the affidavit was apparently made and filed the day prior to the debate and makes mention of Harris’ smaller podium and other details that only became public thereafter,” Mr. Ackman wrote on Sunday in a post on X addressed directly to Mr. Iger.

He continues: “While I can’t determine the veracity of the allegations, they do match substantively what took place during the debate. The moderators of the debate — @DavidMuir and @LinseyDavis — have yet to respond to the allegations. Since they have not yet done so, one must draw a negative inference.

“In light of the seriousness of the allegations and the implications for this presidential election and for ABC’s reputation and thereby
@Disney’s and the office of the CEO,” Mr. Ackman adds, “I strongly encourage you to launch an immediate investigation of this matter.”

He concluded his message by noting that “Our democracy depends on transparency, particularly with regard to events which can impact the outcome of the presidential election … I ask on behalf of all voters that you treat these allegations with the seriousness they deserve.”

According to Puck, Mr. Iger and Dana Walden, the co-chairwoman of Disney Entertainment who oversees ABC News, together watched the debate live from a Disney bolthole at New York City.

Mr. Ackman is just one of the influential figures who has elevated the whistleblower’s claims. Dozens of journalists, political commentators, and politicians have shared the affidavit on social media and demanded action.

Further chaos ensued when rumors swirled on social media that the whistleblower had died in a car crash over the weekend — claims which have since been debunked.

ABC News faced accusations of partiality even before the two candidates took the stage on Tuesday night. In the lead up to the debate, Trump criticized ABC News for employing ABC News anchor and former Clinton operative, George Stephanopoulos, who played a key role in the effort to push Mr. Biden out of the presidential election after a video appeared on TMZ in which Mr. Stephanopoulos, who had just conducted a pivotal interview with Mr. Biden, told a passerby at Manhattan that he did not believe Mr. Biden could serve another four years.

Prior to the debate, Trump also singled out ABC News contributor, Donna Brazile, who was dropped from her commentary position at CNN in 2016 after she was exposed by Wikileaks for tipping off Senator Clinton about questions she would face at a “town hall.”

“Will panelist Donna Brazile give the questions to the Marxist Candidate like she did for Crooked Hillary Clinton?” Trump wrote on Truth Social, sparking speculation that he would drop out of the debate.

He also repeated an accusation he has made for years that ABC News personality Martha Raddatz cried on the air on election night 2016 — the video is inconclusive and Ms. Raddatz has denied crying.

Despite this criticism, ABC News used both Ms. Raddatz and Ms. Brazile to host their pre- and post-debate shows on September 10. Also participating in those shows was ABC News correspondent Rachel Scott, who was widely criticized for her aggressive hectoring of Trump during his July appearance at the National Association of Black Journalists conference.

The charges of bias exploded after the debate, with many pointing out that over the course of the 90-minute event, the moderators fact-checked the GOP nominee five times but failed to offer a correction of Ms. Harris once — even though Ms. Harris made false statements. The claim was voiced by Trump himself, who, during a conversation with Fox on Wednesday, called the debate a “three-on-one” ordeal.

“It was a rigged deal, as I assumed it would be, because when you looked at the fact that they were correcting everything and not correcting with her,” Trump said.

Radio host and former Fox News star, Megyn Kelly, expressed similar concerns, adding that the moderators were likely under pressure from Ms. Walden, the powerful Disney executive, who is a longtime close friend of Ms. Harris, her neighbor in the exclusive Brentwood neighborhood at Los Angeles, where Mr. Iger also has his primary residence.

The vice president has credited Ms. Walden and her husband for the circumstances that led her to meet her husband, Doug Emhoff.

“David Muir and Linsey Davis did exactly what their bosses’ wanted them to do,” Ms. Kelly wrote in a blog post on her website. “They did Dana Walden’s bidding.”

The network has been forceful in denying that they had made any arrangement with the Harris campaign prior to the debate. Last Friday, an ABC spokesman told the Daily Beast that they had “absolutely not” given Ms. Harris “any questions before the debate.” The network also denied that any Harris campaign aides were in contact with Mr. Muir and Ms. Davis during the 90-minute debate.

Such actions would violate the network’s debate rules, which state that “no topics or questions will be shared in advance with campaigns or candidates.”

Disney has also claimed that Ms. Walden’s oversight is limited to the corporate side of the business and that she has no influence over editorial matters. In addition to ABC News, she, along with her colleague Alan Bergman, oversees all of Disney’s movie and television operations except for ESPN, and focuses on the entertainment portfolio.

Ms. Davis, however, broke her silence on the debate last week when she told the Los Angeles Times that the decision to fact-check Trump was driven by what she and her ABC News colleagues thought was the failure of the moderators of June’s CNN debate, between Trump and Mr. Biden, to call out Trump on his falsehoods.

“People were concerned that statements were allowed to just hang and not [be] disputed by the candidate Biden, at the time, or the moderators,” Ms. Davis told the Times on Wednesday. ABC News’s critics seized upon her remarks, characterizing them as an admission of the network’s bias.

ABC News has been buoyed by positive feedback for its debate moderation by elite establishment media. Shortly after the debate concluded, CNN journalist and anchor of the network’s prime time news show, “NewsNight with Abby Philip”, Abby Philip, came to ABC’s defense in a message on X, writing, “Just fyi: when there is asymmetrical lying, there will be asymmetrical fact checking.”

As noted in Mr. Ackman’s letter, neither the network, Mr. Muir, nor Ms. Davis, have addressed the affidavit. Both Disney and ABC News have not yet responded to the Sun’s request for comment.