A disputed Russian intelligence document obtained by the FBI during the 2016 election influenced the Bureau's then-director, James Comey, to personally announce the end of the investigation into Hillary Clinton's email server last summer, the Washington Post reports. The existence of the document has been confirmed by CBS News.

Comey's July 2016 announcement that the FBI would not recommend that charges be brought against Clinton while still criticizing her for maintaining a private email server was characterized as unprecedented at the time. Typically, when an FBI investigation ends without charges, the Bureau and the Department of Justice (DOJ) do not comment on the matter.

But Comey felt that it was best for him to personally explain the Bureau's reasoning to reporters. And part of the reason for that decision, current and former officials told the Post, is the existence of a document alleging that then-Attorney General Loretta Lynch had assured the Clinton campaign that she would limit how far the FBI investigation into the email server went.

The FBI, however, deemed the document -- supposedly an analysis conducted by Russian intelligence -- to be bad intelligence. The Americans mentioned in the document insisted they did not know each other and had never spoken, and there was no evidence to back up its veracity. The person who had supplied the document, officials told the Post, had provided intelligence in the past that the Bureau could not corroborate.

Get Breaking News Delivered to Your Inbox

The documented summarized an alleged email from then-Democratic National Committee chairwoman Rep. Debbie Wasserman Schultz, D-Florida, to Leonard Benardo, an official at an organization founded by left-wing billionaire George Soros. In this email, according to the document, Wasserman Schultz said to Benardo that Lynch had told a Clinton campaign staffer, Amanda Renteria, that she would limit the FBI's investigation into the email server.

The FBI never obtained the email in question, was unsure that it ever existed, and never interviewed anyone mentioned in the document. Additionally, both Wasserman Schultz and the Soros affiliate she was alleged to have talked with told the Post that they did not know each other nor have they ever communicated.

Comey's fear, according to official who talked to the Post, was that the document would leak, which could call into question the Bureau's impartiality in the case. The possibility of such a leak factored in to his decision to publicly announce the end of the Clinton investigation without discussing it with the Department of Justice.

"It was a very powerful factor in the decision to go forward in July with the statement that there shouldn't be a prosecution," a person familiar with the matter told the Post. "The point is that the bureau picked up hacked material that hadn't been dumped by [the Russians] involving Lynch. And that would have pulled the rug out of any authoritative announcement."

The FBI later determined the document was either bad intelligence or possibly even a fake, and could be part of what sources tell CBS News was Moscow's efforts to plant fake news "into the bloodstream" of the election to discredit Clinton and influence the presidential election.

Another major factor in Comey's decision was Lynch's meeting on a Phoenix tarmac with former President Bill Clinton the week before Comey publicly cleared Clinton. A month after Comey's announcement, the FBI informed Lynch about the existence of the document, but assured her that it "didn't have investigative value."

Lynch told the FBI that she had never communicated with Renteria, according to someone familiar with the matter. And Renteria told the Post she had never communicated with Lynch. "I don't know Loretta Lynch, the attorney general," Renteria told the paper. "I haven't spoken to her.''

According to the Post, Sen. Charles Grassley, R-Iowa, asked Comey about the document at a hearing before Comey was fired from his job. Comey replied that while he had talked about it privately with members of the congressional intelligence committees, he could not discuss it in public.

"The subject is classified, and in an appropriate forum I'd be happy to brief you on it," he told the Senate Judiciary Committee. "But I can't do it in an open hearing."