The need for secrecy was so great that CIA Director John Brennan hand-delivered information from a critical informant close to Russian President Vladimir Putin in an envelope to President Barack Obama in August 2016.

Now, one day after President Trump gave Attorney General William Barr "full and complete authority to declassify information" related to the origins of the federal investigation into possible ties between the Trump campaign and Russia, the New York Times reports this source is in jeopardy.

The declassification order, celebrated by GOP allies and derided by Democrats as a "plot to dirty up the intelligence community," could put the Justice Department at odds with the CIA over the protection of the identity of this key informant who provided information about the Kremlin's role in interfering in the 2016 election.

Specifically, this informant was the U.S. intelligence community's source in determining that Putin personally "ordered an influence campaign in 2016 aimed at the US presidential election" to undermine Democratic candidate Hillary Clinton in favor of Trump. Obama made this public before he left office.

The informant is described as being a long-nurtured source who rose up the Russian ranks. Believed to still be alive, the well-being of the informant is one concern as Barr digs into the earliest days of the Russia investigation. Former national security officials and Democratic lawmakers are also worried that Trump may be putting other sources and methods at risk as part of a politically motivated effort to "investigate the investigators."

Overseen by Brennan, the information delivered by this high-placed informant was treated with the utmost care, but done so outside of the norm.

Word of this high-placed informant first came out in June 2017 in a Washington Post story that said Brennan began feeding this material to Obama and a small group of aides with a report in an envelope to be read and promptly returned to the CIA. The material was deemed so sensitive that it was kept out of the President’s Daily Brief due to concerns that too many people would be made aware of its contents.

Although the Post report said a courier was used to deliver this information, the Times piece said Brennan himself gave it to Obama.

As a former official would tell it, Obama "was deeply concerned and wanted as much information as fast as possible" and "wanted the entire intelligence community all over this." A covert task force was put together by Brennan that coordinated with operations specialists at the CIA, National Security Agency, and FBI on Russia intelligence gathering and kept Obama apprised of their work.

Brennan, an outspoken critic of Trump's, has come under increased scrutiny in recent weeks for actions he took in the genesis of the counterintelligence investigation into Trump's campaign.

With Barr sending a shock wave through Washington by asserting "spying did occur" against the Trump campaign and enlisting U.S. Attorney John Durham to lead an investigation into the Russia inquiry's earliest days, Brennan went on the defensive. "Does the CIA spy? Yes," he told MSNBC. "Do we spy against our foreign adversaries? Yes. Do we spy against domestic individuals? No we do not. We work very closely with the FBI. And when the Russians were trying to interfere in that election and to change the outcome of it in their favor, the CIA and the FBI worked very collaboratively to see what the Russians were doing and who they were working with."

Republicans believe the impending declassification of Russia investigation documents will show an email exchange between Brennan and former FBI Director James Comey discussing the use of British ex-spy Christopher Steele's unverified dossier in the U.S. intelligence community's assessment on Russian interference in the 2016 election. Former Rep. Trey Gowdy, who claims to have seen the classified material, said this puts Brennan in jeopardy more than it does Comey.

Trump has been hinting for weeks that he would declassify "everything" in regards to the Russia investigation. Although the Times report's sourcing is anonymous, Rep. Mark Meadows, R-N.C., a close Trump ally and lead GOP investigator, said the timing of its publication on Friday is very revealing and a potential effort to burn a CIA informant as a means of protection. "The Brennan/Clapper/Comey and Co.'s house of cards is falling. And they know it," the North Carolina Republican tweeted, referring also to former Director of National Intelligence James Clapper.

Barr has been reviewing the counterintelligence investigation into the Trump campaign for weeks now. Not only has he tasked Durham with reviewing the origins of the Trump-Russia investigation, but he has also enlisted the help of CIA Director Gina Haspel, Director of National Intelligence Dan Coats, and FBI Director Christopher Wray.

Although Trump said his order empowering Barr could lead to the declassification of "millions of pages of documents," Coats tamped down expectations about the scope of what can be made available to the public.

"Much like we have with other investigations and reviews, the Intelligence Community will provide the Department of Justice all of the appropriate information for its review of intelligence activities related to Russian interference in the 2016 presidential election," Coats said in a statement Friday. "As part of that process, I am confident that the Attorney General will work with the IC in accordance with the long-established standards to protect highly-classified information that, if publicly released, would put our national security at risk."

If the identity of the CIA's informant is revealed as part of Barr's newly obtained declassification authority, it would follow last year's leak that the FBI had an informant in Stefan Halper, an American professor at Cambridge University who met with associates of Trump's campaign.

This happened after top House Intelligence Republican Devin Nunes, R-Calif., subpoenaed the Justice Department for documents concerning an American who was a confidential intelligence source for special counsel Robert Mueller’s investigation. The DOJ fought back, warning that providing the information would threaten the life of the source and jeopardize national security.

Halper is a focus of Justice Department Inspector General Michael Horowitz's FISA abuse investigation. In April it was revealed a woman who said her name was Azra Turk and posed as an assistant to Halper when meeting with Trump campaign adviser George Papadopoulos was working undercover for the FBI.