The company behind the Des Moines Register, which published Ann Selzer’s poorly-aged Iowa poll, has launched an investigation after the poll's findings were allegedly leaked on X prior to publishing, according to a new report. 

Seltzer's pre-election poll, which set off a multi-day media firestorm, inaccurately showed Vice President Kamala Harris leading in Iowa. The poll was published by the Des Moines Register on the evening of November 2. But an unknown social media user, who assumes the handle "IllinoisLib," posted the results on X roughly an hour before it went live, according to a report from Semafor.

"Selzer is about to drop Kamala +3 Source: Major campaign surrogate. Not joking. Mark my words," the post reads.

'ENJOY RETIREMENT': VETERAN POLLSTER MOCKED AFTER HARRIS PREDICTION IN IOWA WAS 'SHOCKINGLY WRONG'

Trump victory speech

WEST PALM BEACH, FLORIDA - NOVEMBER 06:  Republican presidential nominee, former U.S. President Donald Trump arrives to speak during an election night event at the Palm Beach Convention Center on November 06, 2024 in West Palm Beach, Florida.  (Chip Somodevilla/Getty Images)

In a follow-up post, the author wrote that Democratic Governor JB Pritzker of Illinois revealed the poll's findings during a Duke Democrats meeting earlier in the day. Pritzker's office did not respond to Fox News Digital's request for comment.

"No I was deada--," the author wrote. "JB Pritzker just fully mentioned it at a Duke Democrats meeting and was like 'Oh wait that's not being released till later today oops" and my jaw fell to the floor.'"

The publishing chain Gannett, which owns the Iowa paper, is reportedly probing the apparent leak, two people familiar with the matter told Semafor.

"Gannett is investigating how Pritzker and possibly other political actors could have learned of the poll early, and is reviewing employees’ emails, one of the sources said," the Semafor report reads.

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Vice President Kamala Harris delivers a concession speech after the 2024 presidential election, on Wednesday, Nov. 6, on the campus of Howard University in Washington, D.C. (AP/Jacquelyn Martin)

The Des Moines Register-sponsored poll in Iowa three days before the election caused a firestorm when it showed Harris winning by 3 points in the reliably red state. The shock poll showed a 7-point shift from Trump to Harris from September, when he had a 4-point lead over the vice president (47% to 43%) in the same survey. The Des Moines Register/Mediacom Iowa poll released Saturday had Harris up 47% to 44 %, in a state Trump had carried easily in 2016 and 2020 and wasn't considered a swing state in 2024. 

IOWA POLLSTER ANN SELTZER SUGGESTS HER DATA COULD HAVE GALVANIZED REPUBLICAN VOTERS INTO PROVING IT WRONG

Much of the media took Selzter's words as gospel, as pundits on MSNBC, CNN and ABC’s "The View" all celebrated the forecast, hoping it was a positive sign for Harris on Election Day. After the results came in, Trump supporters and conservatives quickly slammed and mocked Selzer’s poll.

After Trump's victory in the state, the Des Moines Register said Selzter was "reviewing her data" to determine why her poll "produced results so far out of line with former President Donald Trump's resounding victory."

Selzer wrote in an op-ed for the Des Moines Register that she had been getting bombarded with criticism and questions about where she went wrong. In response, she suggested her poll itself may have shifted the state for Trump.

iowa des moines register

DES MOINES, IOWA - JANUARY 12: A copy of The Des Moines Register is tucked into an office door as Winter storm Gerri arrives in Iowa four days before the caucuses on January 12, 2024 in Des Moines, Iowa.  ((Photo by Chip Somodevilla/Getty Images))

"My inbox and my voice mail have been full of questions the last few days — those who wanted to know why I ‘manipulated’ the data to show a false Harris lead, and those who wondered if the data were too good to be true," Selzer wrote. "In response to a critique that I ‘manipulated’ the data, or had been paid (by some anonymous source, presumably on the Democratic side), or that I was exercising psyops or some sort of voter suppression: I told more than one news outlet that the findings from this last poll could actually energize and activate Republican voters who thought they would likely coast to victory. Maybe that’s what happened."

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Selzer added that her team is working to review what happened and "raise any plausible question" about the data. She also admitted she "had a sense of the late shift" after listening to voters in the days leading up to the election.

Gannett did not respond to Fox News Digital's request for comment.

Fox News' Lindsay Kornick contributed to this report.