In a series of interviews with the Post, the woman claimed that she had had a sexual relationship with Moore in 1992 at the age of 15 that resulted in her pregnancy and a subsequent abortion, the paper reported.
After uncovering numerous inconsistencies in her story, the Post decided not to publish a story on her allegations and instead presented the woman, identified by the paper as Jaime T. Phillips, with information that appeared to show she was working as a conservative activist to expose bias in major news organizations, the paper reported.
That information included a GoFundMe page, discovered by a Post researcher from May 2017, written by a person named Jaime Phillips that read, "I've accepted a job to work in the conservative media movement to combat the lies and deceit of the liberal MSM [mainstream media]. I'll be using my skills as a researcher and fact-checker to help our movement. I was laid off from my mortgage job a few months ago and came across the opportunity to change my career path."
On Monday morning, the Post says, its reporters witnessed Phillips entering the New York offices of Project Veritas, a conservative group that sets up sting operations in attempts to expose what it perceives as liberal bias in the American news media, the paper said.
The Post said that after Phillips was observed walking into the Project Veritas offices, the paper made the decision to publish her previous comments, which were provided off the record, as well as a video showing an interview last Wednesday between Post reporter Stephanie McCrummen and Phillips in which McCrummen challenged Phillips on many of the details of her story.
"We always honor off-the-record agreements when they're entered into in good faith," said Martin Baron, the Post's executive editor. "But this so-called off-the-record conversation was the essence of a scheme to deceive and embarrass us. The intent by Project Veritas clearly was to publicize the conversation if we fell for the trap. Because of our customary journalistic rigor, we weren't fooled, and we can't honor an off-the-record agreement that was solicited in maliciously bad faith."
The president of Project Veritas, James O'Keefe, is also shown in a video in the Post article, refusing to answer questions about whether Phillips is an employee of the group.
In a fundraising e-mail sent to supporters Monday, O'Keefe said, "Our investigative journalist embedded within the publication had their cover blown," apparently referring to the Post story and seeming to confirm that Phillips was working for Project Veritas.
Moore's Senate campaign has been embroiled in controversy since the Post published a story earlier this month detailing four women's allegations that he made inappropriate advances toward them when they were teenagers in the late 1970s and Moore was the deputy district attorney of Etowah County, Alabama.
Four more women have since come forward alleging sexual misconduct by Moore, who has continued to deny the allegations and push forward with his campaign.
"These allegations are completely false. They're malicious. Specifically, I do not know any of these women, nor have I ever engaged in sexual misconduct with any woman," Moore said at a campaign rally Monday night in Henagar, Alabama.
A Moore campaign spokesperson did not respond to a request for comment from ABC News on the Post's story and interviews with Phillips.
The Alabama Senate special election between Moore and his Democratic opponent, Doug Jones, will be held Dec. 12.