One of the most remarkable takeaways from the new documents released in the Trump-Russia investigation is the degree to which FBI officials were determined to believe dossier author Christopher Steele — even after it became clear he had lied to them. In their drive to win a warrant to wiretap sometime Trump volunteer Carter Page — along with Paul Manafort, one of only two Trump figures known to be wiretapped in the investigation — the bureau rested most of its case on Steele's information, and the officials who filed the warrant application seemed resolved to believe Steele even after his credibility came into question.

The new document is the (mostly) unredacted version of the criminal referral of Steele sent to the Justice Department by Senate Judiciary Committee chairman Chuck Grassley and subcommittee chairman Lindsey Graham. Like the earlier House Intelligence Committee memo, the Grassley-Graham referral shows that the FBI focused extensively on the dossier in its effort to convince the secret Foreign Intelligence Surveillance Act court to give permission to wiretap Page. The FBI warrant application "relied heavily" on the dossier, according to the referral, and "the bulk of the application consists of allegations against Page that were disclosed to the FBI by Mr. Steele and are also outlined in the Steele dossier."

In part, the FBI trusted Steele because it had to; the bureau had no other evidence that would have sufficed to win a warrant to wiretap Page. "The application appears to contain no additional information corroborating the dossier allegations against Mr. Page," the Grassley-Graham referral said, "although it does cite to a news article that appears to be sourced to Mr. Steele's dossier as well." At another point in the referral, Grassley and Graham wrote that the FBI "relied more heavily on Steele's credibility than on any independent verification or corroboration for his claims."

"Indeed, the documents we have reviewed show that the FBI took important investigative steps largely based on Mr. Steele's information — and relying heavily on his credibility," Grassley and Graham wrote.

The FBI placed so much faith in Steele because he was a former British spy — a fellow professional — who had worked with the bureau a few years earlier in the world soccer corruption investigation. The FBI specifically referenced Steele's history in the Page application to the FISA court, known as FISC.

"The FBI stated to the FISC that 'based on [Steele's] previous reporting history with the FBI, whereby [Steele] provided reliable information to the FBI, the FBI believes [Steele's] reporting to be credible,'" Grassley and Graham wrote, quoting from the surveillance application.

But there were two problems with Steele's credibility, according to the referral. The first was the lack of corroborating evidence. The other was convincing evidence that Steele lied to the FBI.

The credibility issue focused on whether Steele shared his dossier allegations with the press. When, in the late summer of 2016, the FBI asked Steele to join the Trump investigation — an extraordinary move, given that it was the middle of a presidential campaign and Steele was working for the Hillary Clinton campaign — one obvious condition was that Steele not share his information with the press.

Then, on September 23, 2016, Yahoo News published an article that was obviously based on Steele's dossier information. That seemed a clear violation of Steele's agreement with the FBI. What to do?

Steele apparently told the FBI he had shared his information with only two parties — the FBI and his client, which was the opposition research fund Fusion GPS, working for the Clinton campaign and the Democratic National Committee. But the Yahoo article "contained some of the same dossier information about Mr. Page compiled by Mr. Steele on which the FBI relied in its application," Grassley and Graham wrote. Wouldn't that lead a reasonable observer to suspect Steele had talked to Yahoo?

Steele denied to the FBI that he had done that. In turn, the FBI denied to the FISA court that Steele had talked to Yahoo. Grassley and Graham offered a quote from the actual application, in which the FBI wrote, "Given that the information contained in the September 23rd news article generally matches the information about Page the [Steele] discovered doing his/her research, [redacted portion] The FBI does not believe that [Steele] directly provided this information to the press."

The use of the word "directly" suggested that perhaps the client had given Steele's information to Yahoo. But in fact, Steele himself had directly provided the information to the press. In September he personally briefed reporters from Yahoo, the Washington Post, the New York Times, CNN, and the New Yorker. In October, he did it again — the Washington Post reported that Steele was "visibly agitated" in an anti-Trump fervor during his second visit to the paper. Also in October, Steele added a briefing for the left-wing publication Mother Jones.

But the FBI denied Steele's press contacts in the surveillance application, which was dated October 21. Then, on October 31, Mother Jones published an article clearly based on Steele's information. Reading it, the FBI could no longer pretend that its valuable informant was not also sharing his anti-Trump information with the press. The FBI formally terminated its agreement to work with Steele, and thereafter kept up its relationship with him through a backchannel connection, the Justice Department official Bruce Ohr, whose wife was an employee of Fusion GPS.

But what to tell the court? Could the FBI say, Oh, this guy who provided the bulk of our case against Carter Page has lied to us?

In January 2017, when the FBI went back to the FISA court to ask permission to extend the surveillance of Page, the bureau conceded it had ended its relationship with Steele because of his "unauthorized disclosure of information to the press." The FBI explained that Steele was upset about the re-opening of the Clinton email investigation, and in his anger at the FBI took his information to reporters. "[Steele] independently and against the prior admonishment from the FBI to speak only with the FBI on this matter, released the reporting discussed herein [that is, the dossier] to an identified news organization," the FBI wrote in the application to extend surveillance.

But the anger story wasn't true. No matter how angry Steele might have been about the re-opening of the Clinton investigation, the fact is, Steele talked to the press — Post, Times, New Yorker, CNN, Yahoo — before the Clinton investigation was re-opened. It was part of his work for Fusion GPS.

The point of the Chris-was-angry-so-he-talked-to-the-press story was to allow the FBI to claim that Steele's pre-anger work — the dossier — was entirely credible. "The FBI continued to cite to Mr. Steele's past work as evidence of his reliability," Grassley and Graham wrote, "and stated that 'the incident that led to the FBI suspending its relationship with [Mr. Steele] occurred after [Mr. Steele] provided' the FBI with the dossier information described in the application. The FBI further asserted…that it did not believe that Steele directly gave information to Yahoo News that 'published the September 23 news article.'" The FBI used the same argument in all its requests to renew the Page surveillance.

But of course, Steele had given the information to Yahoo. And it wasn't because he was mad about the Clinton investigation.

Still, the FBI kept faith. "The FBI still seemed to believe Mr. Steele's earlier claim that he had only provided the dossier information to the FBI and Fusion — and not to the media — prior to his October media contact that resulted in the FBI suspending the relationship," Grassley and Graham wrote. "Accordingly, the FBI still deemed the information he provided prior to the October disclosure to be reliable."

Why? The FBI went into the relationship with Steele believing he was reliable. His information about Trump was spectacular, and if true would be the basis of a historically important FBI investigation. And Steele had denied talking to the press. And one more thing, Grassley and Graham drily noted: "Lying to the FBI is a crime." FBI officials did not want to admit that Steele had lied to them, in part because if they did, their prized informant would be in legal jeopardy, instead of the investigation's real target, Donald Trump.

So in the end, the FBI vouched for Steele and his information without verification and without fully grappling with the question of Steele's honesty. "The FBI relied on admittedly uncorroborated information, funded by and obtained for Secretary Clinton's presidential campaign, in order to conduct surveillance of an associate of the opposing candidate," the Grassley-Graham referral said. "It did so based on Mr. Steele's personal credibility and presumably having faith in his process of obtaining the information."

Top FBI officials wanted to believe Steele. They needed to believe Steele. So they believed Steele.