Byrne's story, as told to CNN anchor Chris Cuomo on "Cuomo Prime Time," and in previous interviews posted on Fox Business News and Fox News, also includes allegations that top Obama administration officials, including James Comey, the former The FBI director approved the agency's requests from him.
It has not been confirmed by the agencies, and spokesmen for the Department of Justice and the FBI declined to comment. Comey Thursday night by CNN, Comey called Byrne's claim "ridiculous."
"The FBI doesn't work that way," Comey said.
An American official told CNN on Thursday that Byrne met earlier this year with Justice Department officials and shared similar information about a romantic relationship with Butina encouraged by the FBI. The US official said the Byrne Department of Justice official found aspects of Byrne's history to be credible in part because he shared operational details that were unknown.
Byrne said he first met Butina at an event in Las Vegas in 201
Byrne said he then informed the FBI of her outreach to him. He had built a relationship with the FBI after helping the agency in two previous cases, he said, adding that agents had told him he had a "non-standard relationship with the government."
The FBI, according to Byrne, greenlit and "encouraged" him to build a relationship with Butina, something he did – and said he would meet with the young grad student every six weeks and discuss philosophy and politics with her.
Byrne said he was worried when Butina mentioned her relationship with the Kremlin-affiliated banker Alexander Torshin, who she said had instructed her to try to build inward into the upper reaches of American politics. Butina's efforts in the United States and her communications with Torshin have been reviewed in court filings in the lawsuit brought by prosecutors in Washington, DC, against Butina last year.
Byrne said he reported what he had learned about Butina's assignment in the United States to the FBI, but that "they continued to dismiss it."
"It was so strange that I thought, it's almost like they've let this can-o scandal develop and one day they're going to shake it and crack it and spray it over the Republican the party, "he said.
Byrne later claimed that the FBI asked him to break the relationship with Butina, before contacting him again in July 2016, saying that he needed to "revive" her relationship to help the agency's efforts over time. investigated Russian attempts to interfere in the US presidential election.
"They came back to me and said, 'Well, what a mistake we made. Russia, you are right … the highest national priority,' he said.
" They said: & # 39; We want to be clear – this never happens in the US, & # 39; & # 39; added Byrne. "We're good guys, we don't act like villains, but we must ask you to restore a romantic relationship with Maria Butina." "
Asha Rangappa, a former FBI official and legal analyst at CNN, said elements of Byrne's claims about how the FBI encouraged his first attempt to establish a relationship with Butina, and were consistent with how the agency would typically conduct an investigation.  But she said she was skeptical of his claim that the agency later encouraged him to have a "romantic relationship" with Butina.
"If he had a romantic affair with her on his own and provided information to them "I don't know that it will necessarily be off-limits," she said. But if the FBI had asked him to have a romantic relationship, "it seems incredibly suspect to me just because there is a lot of legal responsibility involved in it. Imagine that he said / said situations, "she said.
Byrne's comments and resignation as chief executive of Overstock comes after he published a press release earlier this month claiming he helped the FBI carry out" political espionage. "
" Getting public about my involvement in other matters was hardly my first choice, "Byrne wrote in his letter of resignation." I now plan to leave things to the reputable Department of Justice (which I have no doubt already angered) Earlier this year, Attorney General William Barr cited Connecticut's top federal prosecutor, John Durham, with a review of how the intelligence community operated in the early days of Russia's investigation. is not clear if Byrne's allegations have been investigated by Durham.
Butina's attorney, Robert Driscoll, said of Byrne's resignation, "I wish him well. I think he raised questions that are worthy of investigation, at risk to his career, as has become clear. "
CNN's Jackie Wattles contributed to this report.