The FBI's Crossfire Hurricane team investigating the Trump 2016 campaign received multiple indications that former British spy Christopher Steele -- one of their key informants in their investigation -- was part of an elaborate "Russian disinformation campaign," according to several newly declassified footnotes from Department of Justice Inspector General Michael Horowitz's report on FBI misconduct.

The FBI heavily relied on Steele's now-discredited dossier to obtain a surveillance warrant to spy on former Donald Trump aide Carter Page, in which FBI officials asserted that Page was an "agent" of Russia. However, the FBI did not share the information about the Russian disinformation campaign with the Foreign Intelligence Surveillance Court (FISC) when it moved to obtain the warrant, just as it did not tell the court that another Trump aide had denied collusion during a recorded conversation with an FBI informant.

“It’s ironic that the Russian collusion narrative was fatally flawed because of Russian disinformation," Sens. Chuck Grassley, R-Iowa, and Ron Johnson, R-Wis., who had pushed for the declassification, said in a statement to Fox News on Friday. "These footnotes confirm that there was a direct Russian disinformation campaign in 2016, and there were ties between Russian intelligence and a presidential campaign – the Clinton campaign, not Trump’s.”

At the same time, Grassley's office added that "the senators expect a fuller declassification in the coming days," including a version of the footnotes that does not redact the names of those who raised the alarm about Steele. Some in Grassley's office, including Grassley himself, have seen the fully declassified footnotes, and want them publicly released immediately, Fox News is told.

One of the footnotes, which was previously redacted in its entirety, read: “The [REDACTED] stated that it did not have high confidence in this subset of Steele’s reporting and assessed that the referenced subset was part of a Russian disinformation campaign to denigrate US foreign relations." That subset referred to the activities of former Trump lawyer Michael Cohen, whom Steele's dossier claimed had traveled to Prague to meet with Russian agents. Special Counsel Robert Mueller was unable to substantiate that claim, and Cohen has denied it.

The footnote goes on to state that a 2017 report “contained information … that the public reporting about the details of Trump’s [REDACTED] activities in Moscow during a trip in 2013 were false, and that they were the product of RIS ‘infiltra[ing] a source into the network’ of a [REDACTED] who compiled a dossier of information on Trump’s activities.”

Another footnote stated: "According to a document circulated among Crossfire Hurricane team members and supervisors in early October 2016, Person 1[Sergei Millian] had historical contact with persons and entities suspected of being linked to RIS [Russian intelligence]. The document described reporting [REDACTED] that Person 1 'was rumored to be a former KGB/SVR officer.' In addition, in late December 2016, Department Attorney Bruce Ohr told SSA 1 [FBI Agent Joe Pietnka] that he had met with Glenn Simpson and that Simpson had assessed that Person 1 was a RIS officer who was central in connecting Trump to Russia."

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Pientka was conspicuously removed from the FBI's website after Fox News contacted the FBI about his extensive role in Crossfire Hurricane FISA matters, but sources say he remains in the agency's field office in San Francisco in a senior role. Republicans have sought to question him repeatedly.

Millian contacted Fox News after this article was published, and strongly denied any links to illicit activities or intelligence services, saying there was an attempt to "frame" him that had backfired.

The newly released footnotes gave other reasons to doubt the knowledge and credibility of Steele's main sources, as well as the accuracy of Horowitz's own report.

"When interviewed by the FBI, the Primary Sub-source stated that he/she did not view his/her contacts as a network of sources, [REDACTED] with whom he/she has conversations about current events and government relations," one of the previously hidden footnotes reads.

That statement directly contradicted the executive summary of Horowitz's IG report, which asserted that Steele's Primary Sub-source "used his/her network of sub-sources to gather information that was then passed to Steele."

While Friday's disclosure was significant, the partial declassification of the footnotes didn't fully comply with previous requests to the DOJ from Grassley and Johnson, whose letter to Barr sought the full and complete declassification of the four footnotes in the IG report in January.

Grassley and Johnson wanted the DOJ to declassify footnotes 302, 334, 342 and 350; all were only partially unredacted, and 342 remains fully redacted.

The fully redacted footnote "refers to information received by a member of the Crossfire Hurricane team regarding possible previous attempts by a foreign government to penetrate and research a company or indiviudals associated with Christopher Steele," the DOJ said, adding that it would continue to "review" the footnote's classification for possible release. It was unclear which foreign government was implicated; the DOJ IG report refers to Russia numerous times without any redaction.

In a letter to Barr in January seeking the full declassification of four footnotes in Horowitz's report, Grassley and Johnson had written: "We are concerned that certain sections of the public version of the [IG] report are misleading because they are contradicted by relevant and probative classified information redacted in four footnotes within the classified report."

Friday's partial declassification, which suggested Steele's sources were part of a Russian interference effort, was immediately highlighted by Trump allies and Republicans, who have long pushed the administration to publicize more details of the FBI's flawed investigation, even as U.S. Attorney John Durham is pursuing a criminal probe into the conduct of U.S. intelligence agencies.

The FBI's legal counsel later described the warrant to surveil Page as "essentially a single source FISA" wholly dependent on the dossier, which also made numerous other unsubstantiated claims about Russian hackers in a nonexistent consulate in Miami, Cohen's purported trips to Prague, and lurid blackmail tapes.

Aspects of the Page FISA that did not rely on the dossier have not fared well, either. For example, The Washington Post ended up in the Page FISA application as a key source alongside the dossier. A 2016 opinion piece by the Post's Josh Rogin entitled, "Trump campaign guts GOP’s anti-Russia stance on Ukraine," had overstated developments at the Republican National Convention in 2016. A single delegate had proposed a sweeping amendment to change the GOP platform to provide lethal weapons to Ukraine, in a major shift from the Obama administration's policy; parts of that amendment were rejected.

But, the Post's opinion piece framed the development as nefarious, and a possible smoking gun. In a Page FISA application, the FBI went on to cite Rogin's article word-for-word – without quotation marks, but with a footnoted citation – as evidence that the Trump campaign could be working with the Russians in an illicit manner. The FBI apparently did not obtain independent verification of the article’s claims.

"The 'central and essential' evidence used to justify invasive surveillance of an American citizen in the FBI’s probe into Russian interference was, itself, an example of Russian interference, according to once-secret footnotes declassified at the urging of two U.S. Senators," Grassley's office said in a statement to Fox News on Friday.

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"For years, the public was fed a healthy diet of leaks, innuendo and false information to imply that President Trump and his campaign were part of a Russian conspiracy to spread disinformation," Grassley and Johnson said separately. "The FBI’s blind pursuit of the investigation, despite exculpatory and contradictory information, only legitimized the narrative. The mounting evidence undercutting this narrative should have stopped the investigation early in its tracks. Instead, it took several years and millions in taxpayer dollars to conclude that the allegations were baseless."

The senators continued: “Had FBI leadership heeded the numerous warnings of Russian disinformation, paid attention to the glaring contradictions in the pool of evidence and followed long-standing procedures to ensure accuracy, everyone would have been better off. Carter Page’s civil liberties wouldn’t have been shredded, taxpayer dollars wouldn’t have been wasted, the country wouldn’t be as divided and the FBI’s reputation wouldn’t be in shambles.

The Justice Department IG, Michael Horowitz, has found that the FBI systematically violated rules designed to protect Americans from unauthorized surveillance, including Page, prompting the FISC to rebuke the FBI and demand changes.

“Why have all these details remained unnecessarily secret for so long?" Page asked Fox News on Friday. "In our dual system of Justice, the Mueller Witch Hunt crew falsely misrepresented my own 'historical contact with persons and entities suspected of being linked to RIS,' when I was actually serving my country in support of the U.S. Intelligence Community. The time has finally come for the Office of the Director of National Intelligence and related agencies to release the full facts about the Obama-Biden Administration’s election interference campaign against candidate Trump and the illicit coup attempt against our President.”

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In Page's case, an ex-FBI lawyer, Kevin Clinesmith, even falsified an email from the CIA to make Page's Russian contacts seem nefarious, when Page in fact had been an informant to the CIA about those contacts, according to Horowitz.

It emerged separately on Thursday that an FBI confidential human source secretly recorded George Papadopoulos in the final days of the 2016 presidential election and pressed him over whether the Trump campaign was involved in Russian election meddling -- something the campaign aide emphatically denied, according to a transcript of that conversation.

Fox News obtained the transcript of the recording, which spreads over 171 pages. Papadopoulos, a former Trump campaign foreign policy adviser, is referred to in the transcript as "Crossfire Typhoon" or "CT."

The recording covers a more than four-hour conversation on Oct. 31, 2016. According to the obtained transcripts, the confidential human source (CHS) met with Papadopoulos and asked whether he thought Russians hacked the Democratic National Committee (DNC) ahead of the Democratic National Convention.

“No,” Papadopoulos replied.

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The comments made by Papadopoulos are noteworthy because, according to officials, they were never provided or included in evidence to the FISC when seeking warrants to surveil Page over suspicion of Trump campaign ties to Russia.

When asked whether he thought the Russians had “special interests” in the election, Papadopoulos replied: “That’s all bullsh--. No one knows who’s hacking them,” and added that it “could be the Chinese, could be the Iranians, it could be some Bernie, uh supporters. Could be anonymous.”

Papadopoulos was then asked whether he thought Russians “have interest in Trump.”

“They, dude, no one knows how a president’s going to govern anyway. You don’t just say, oh I like—,” he said before being cut off. “I don’t know. Even Putin said it himself. It’s all, it’s like conspiracy theories.”

The source went on to press Papadopoulos, saying: “I feel like there’s some heavy Trump supporters out there that kind of want to rig this f—king election in Trump’s favor and then at the same time, I don’t know.”

Papadopoulos quipped: “Dude, you, you..there is no rigging in his favor.”

Durham's criminal probe concerning the FBI's Russia probe remains ongoing. Speaking to Fox News' "The Ingraham Angle" on Thursday, Barr said he has seen troubling signs from the investigation.

"My own view is that the evidence shows that we're not dealing with just the mistakes or sloppiness," Barr told host Laura Ingraham. "There was something far more troubling here. We're going to get to the bottom of it. And if people broke the law and we can establish that with the evidence, they will be prosecuted."

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It has emerged since former National Security Adviser Michael Flynn's guilty plea that the FBI officials who interviewed Flynn, anti-Trump agent Peter Strzok and "SSA [Supervisory Special Agent] 1," have each separately been implicated by Horowitz in apparent misconduct and mismanagement in both the Flynn case and the Carter Page matter.

Strzok's anti-Trump bias is well-documented. The identity of SSA 1 is protected in the Flynn legal proceedings by a court order, but Fox News has reported that documents point to Joe Pientka, who moved last year from the Washington, D.C., area to San Francisco. Pientka briefly appeared on the FBI's website as an "Assistant Special Agent in Charge" of the San Francisco field office late last year, according to the Internet archive Wayback Machine.

However, Pientka no longer appears on any FBI website after being removed shortly after Fox News identified him as the unnamed SSA in the IG report; Fox News is told Pientka received a promotion to a senior role in the bureau's San Francisco field office. Pientka's extensive role in handling the Page FISA has been outlined in Horowitz's report, and top Republican senators, including Sen. Lindsey Graham, R-S.C., have requested that Pientka sit for an interview to explain himself.

Fox News' Brooke Singman contributed to this report.