The FBI omitted from its application to spy on Carter Page the fact that Russian spies had dismissed the former Trump campaign adviser as unreliable – or as one put it, an “idiot” – and therefore unworthy of recruiting, according to congressional sources who have seen the unredacted document.

The potentially exculpatory detail was also withheld from three renewals of the wiretap warrant before a special government surveillance court. The warrants issued by the Foreign Intelligence Surveillance Act court allowed the FBI to spy on Page and others he was in contact with for almost a year, the sources also confirmed.

Carter Page: An FBI wiretap revealed the Russians thought he wouldn't make a good spy, but the FISA court was never told.

The FBI was aware of Russians’ skepticism that Page knew anything of value or was a significant player because the bureau had recorded them voicing such doubts in a wiretap, from an earlier espionage case involving three Russian spies working undercover for the Kremlin in New York.

The FBI cited that 2013 case, minus the disparagement of Page, in its applications to the FISA court. They have been made public only in redacted form, professing evidence that Page was “recruited" by Russian intelligence and had "coordinated" with the Russian government. But “that’s a mischaracterization of the facts in the case,” a congressional source said.

As first reported by RealClearInvestigations after Page became a central focus of the Trump-Russia investigation, court filings that emerged from the earlier case show the Russian government wasn’t interested in cultivating Page as a spy. Rather, it tried to use him as a source of economic information, but soon “discarded" him as low-value and unreliable.

Viewed in full, the FISA warrants show the court was not alerted to this seemingly critical information, the congressional sources now confirm. This happened even though FBI and Justice Department officials had ready access to the 26-page court filing when they signed the applications.

“The FISA applications omit the fact that a Russian intelligence officer called page ‘an idiot,’ " one congressional source said. The official spoke only on condition of anonymity due to the still-classified nature of the information.

The FBI did not respond to repeated requests for comment.

Robert Mueller: Were his tighter rules on disclosing exculpatory evidence honored in the breach?

Former FBI officials and agents with experience in FISA warrants say the affidavits for Page appear to be “material misrepresentations” and failed to properly follow so-called Woods Procedures requiring accuracy of facts by the sworn declarants. Those procedures were strengthened in 2003 by then-FBI director Robert Mueller, now the special counsel pursuing the Trump-Russia affair.

Withholding material and exculpatory evidence from the FISA applications may also have violated Page’s Fourth Amendment protections against omissions of material facts that would undermine or negate probable cause to search.

“It is illegal,” said veteran FBI agent Michael Biasello. “The affiant" -- the person swearing to the affidavit -- "cannot cherry-pick only information favorable to the case.”

Already controversial, the FISA warrants have been cited by Republicans and other critics as “an abuse of process” and “a fraud on the court," because they relied heavily on other espionage allegations made against Page in the unverified and salacious “Steele dossier” that was prepared for and funded by the Clinton campaign. The Democratic opposition's financial role in generating the unsubstantiated charges, which Page has vehemently denied under oath, was another material fact omitted from all four applications to the FISA court, which blinded judges to political motives behind the allegations.

If FISA abuses are prosecuted in this case, senior officials who swore out the Page warrants, including James Comey and Andrew McCabe of the FBI and Sally Yates and Rod Rosenstein of the Justice Department, could be subject to perjury and conspiracy charges, and barred from appearing before the FISA court again, sources say.

In preparing its case for the FISA court, the FBI struggled to find credible evidence to support a probable cause argument for spying on Page, a U.S. citizen, a well-placed source briefed on the matter said. Evidence that he was acting as an agent of the Kremlin was thin. Headquarters leaned heavily on an unverified tip in the Steele dossier that Page had secretly met with two Kremlin-tied officials sanctioned by the U.S. -- Igor Sechin and Igor Diveykin -- to hatch a plot to interfere in the election during a July 2016 trip to Moscow.

But the only part of that sensational accusation the bureau could corroborate was that Page had traveled that month to Moscow, where he gave an academic speech at a business college that also once hosted President Obama. Intent on securing the warrant to probe the Trump campaign for illicit ties to Moscow, the agency scrambled to show the court other Russian connections. As a result, the source said, Page’s role in the 2013 espionage case in New York was "exaggerated to make it look like he was being groomed by Russian intelligence.”

Posing as bankers, the Russians first approached Page, then an international energy consultant, at a January 2013 industry symposium in New York City. Concluding that Page possessed little information of value, the Russians soon wrote him off.

Evgeny Buryakov: Carter Page helped convict the Russian spy, shown in a sketch of the 2016 court proceeding where he pleaded guilty.

“I think he is an idiot and forgot who I am,” the FBI secretly recorded one of the Russians, Victor Podobnyy, saying to another Russian about Page on April 8, 2013. “You get the documents from him and tell him to go fuck himself.”

Page says he was unaware that he was dealing with foreign agents. The document he provided was an academic paper on the future outlook of the energy industry, which was based on publicly available, non-sensitive information.

“My conversations with Podobnyy were minimal, and completely innocuous,” Page told RealClearInvestigations.

The FBI agreed – at least at that time. During its 2013-2016 investigation of the three Russian agents, it portrayed Page as one of many unwitting victims of their tradecraft – including other New York business people, as well as students -- and as someone who was only “interested in business opportunities in Russia." Far from being a target of the FBI probe, Page was merely a witness (anonymously identified as “Male-1"), one among several, and later became a cooperating witness — indeed, an FBI asset — who helped the government put away one of the spies.

The lead agent on the case, Gregory Monaghan, noted in his court filing that the spies posing as bankers never told Page they were “connected to the Russian Government.”

After realizing he’d been duped, Page told RCI he met with Monaghan and other FBI agents at New York’s Plaza Hotel in June 2013 “to provide support” for their investigation. He met with them again, as well as prosecutors, in March 2016, to help put away one of the Russian agents, who agreed to plead guilty to espionage charges.

The FBI's attitude toward Page turned hostile after candidate Donald Trump publicly announced his name on March 21, 2016 along with other members of his foreign policy team. Only then was Page treated as a counterintelligence concern. Not long afterward, FBI Director Comey and his deputy, McCabe, met with Attorney General Loretta Lynch to discuss the news of Page joining the Trump campaign and “efforts to compromise” him by the Russians, according to a recently declassified memo.

Then, sometime in the “late spring” of 2016, Comey held an unusual briefing concerning Page and the alleged national security risk he posed, with the Obama administration’s highest-ranking national-security officials, who, in addition to Lynch, included National Security Adviser Susan Rice, CIA Director John Brennan, and Director of National Intelligence James Clapper.

Peter Strzok: He went after Carter Page aggressively.

Peter Strzok, the lead agent in the Trump-Russia investigation, began aggressively targeting Page in September 2016 after the dossier allegations were brought to his attention.

In an Oct. 14 email to the counsel for the deputy FBI director, Strzok discussed applying “hurry the F up pressure” on Justice Department attorneys to obtain the FISA surveillance warrant on Page before Election Day. On Oct. 21, his team filed the initial application for a wiretap.

By autumn, in the heat of the presidential election campaign, the FBI had Page under constant surveillance, vacuuming up all his text messages and emails and listening in on his phone calls, including communications with Trump officials.

As a top FBI counterintelligence official, Strzok supervised from Washington the earlier case involving the three undercover Russians in New York, and was familiar with Page’s help in the case, officials say. He did not target Page as a suspect until after Page joined the Trump campaign. Text messages obtained by the Justice Department inspector general reveal that Strzok was stridently opposed to Trump’s bid for president.

In a text message from March 2016 — the month Trump announced Page as one of his foreign policy advisers — Strzok called Trump “an idiot” and said “Hillary should win 100,000,000-0.” On July 26, three weeks after the FBI had cleared Hillary Clinton of charges of mishandling her classified email, Strzok agreed with a fellow investigator that Clinton “just has to win now.” In a Nov. 7 text referencing a pre-Election Day article titled “A victory by Mr. Trump remains possible,” Strzok stated, “OMG THIS IS F*CKING TERRIFYING.”

“Omg I am so depressed,” Strzok wrote the day after the election.