A journalist who "reported" last year that Dylann Roof shot and killed nine African-American churchgoers in Charleston, S.C., because his love interest chose a black man over him has been revealed to be a serial fabricator and plagiarist.

Former Intercept reporter Juan Thompson, who is black, wrote in June 2015 that Roof's cousin, Scott, told him in an interview that the shooter "kind of went over the edge when a girl he liked starting dating a black guy two years back."

Newsrooms, including the New York Daily News, the Root, the Independent, the Daily Mail and Radar Online, pounced on the story, as the alleged conversation and its racial overtones were treated by the press as a piece of crucial information that possibly shined a light on why the 21-year-old Roof did what he did. The Intercept was founded as an investigative news site by Glenn Greenwald, the reporter who was leaked Edward Snowden's bombshell revelation about the U.S. domestic surveillance program.

As it turns out, however, Thompson, who has in the past gloated over other journalists being exposed as plagiarists, fabricated the entire story. There is no cousin named "Scott Roof," according to the family, and Intercept Editor-in-chief Betsy Reed outed Thompson Tuesday morning as a serial plagiarist who had engaged in numerous "deceptions."

"An investigation into Thompson's reporting turned up three instances in which quotes were attributed to people who said they had not been interviewed. In other instances, quotes were attributed to individuals we could not reach, who could not remember speaking with him, or whose identities could not be confirmed," she wrote.

The Intercept has added a retraction to the original story, and the publications that picked up the story last year have followed suit.

"In his reporting Thompson also used quotes that we cannot verify from unnamed people whom he claimed to have encountered at public events. Thompson went to great lengths to deceive his editors, creating an email account to impersonate a source and lying about his reporting methods," Reed added.

She revealed that along with fabricating quotes from real and non-existent persons, Thompson also created fake email addresses to impersonate his editors.

He did not cooperate with their review of his work.

Reed said that the Intercept has taken steps to review all of Thompson's work, and that they've already added lengthy corrections to four stories, and retracted one (the Roof "report") altogether. She added they are continuing to investigate his body of work, and said would they would add retractions or corrections to any other deceptions that they find.

When asked for comment, Thompson sent Gawker an undated note that he reportedly filed to Reed.

His note explained that he couldn't quite work with them on reviewing his work because he was away from New York undergoing treatment for testicular cancer. He also conceded that his work was "sloppy," but blamed his editors for not catching it.

"Was it sloppy? Yes? But I'm a cub reporter and expected a sustained and competent editor to guide me, something which I never had at your company and something with which The Intercept continues to struggle as everyone in this business knows," he explained.

Thompson then blamed institutional racism in media for the many apparent fabrications in his stories.

"[Y]es I encouraged some of my interviewees to use another name; they're poor black people who didn't want their names in the public given the situations and that was the only was of convincing them otherwise," he wrote.

"That also explains why some of them didn't want to talk with your company's research team or denied the events. These weren't articles in Harpers or The Nation. Instead, these are the lives of people forgotten by society and their being in public and talking to white, NY people, no less, could harm and turn them off. They've lost loved ones to violence you and others couldn't possibly imagine," he added. "This dilemma is the Great Problem with the white media organizations that dominate our media landscape."

Thompson promised in his note that he'd work with them at a later date to sort out the inconsistencies and outright falsehoods in his story, but warned that it would look very bad if they moved forward correcting his stories until he had a chance to beat cancer.

"I must say, though, it's a very nefarious and ill liberal and anti humanist position to take if you do otherwise: kicking a cancer patient when he's down. I've been through a lot tougher situations than this and will weather anything thrown my way," he wrote.

He concluded that he is not angry about any of his situation, because he's focusing on "much more important things."

Thompson sent slightly different versions of this same letter to multiple outlets, including one to CNN where he claimed institutional racism forced him "to exaggerate and work to prove [his] worth."