Testimony that FBI Director James Comey delivered in January, information that Harry Reid wanted to make public before the election, and part of the information that led the FBI to get a FISA warrant on Trump adviser Carter Page, all appear to have the same source.

The FBI last year used a dossier of allegations of Russian ties to Donald Trump's campaign as part of the justification to win approval to secretly monitor a Trump associate, according to US officials briefed on the investigation.

That source is the “dossier” put together by former British intelligence operative Christopher Steele, who originally assembled the information to assist one of Trump’s Republican opponents. President Obama and Donald Trump were briefed on the contents on the memos in January, but it now appears that the FBI took the information seriously enough to use it as the basis of investigation months earlier.

The dossier has also been cited by FBI Director James Comey in some of his briefings to members of Congress in recent weeks, as one of the sources of information the bureau has used to bolster its investigation, according to US officials briefed on the probe.
 

The information in the dossier, which includes such events as Trump’s supposed romp with prostitutes in a Russian hotel, seemed incredible at the time that portions first became public. However, since that point, CNN reports that some information from Steele’s work has proven to be true.

For the first time, US investigators say they have corroborated some of the communications detailed in a 35-page dossier compiled by a former British intelligence agent, multiple current and former US law enforcement and intelligence officials tell CNN.