WASHINGTON • The CIA alerted the FBI to a troubling pattern of contacts between Russian officials and associates of the Trump campaign last year, former agency director John Brennan has testified, shedding new light on the origin of a criminal probe that now reaches into the White House.
In testimony before the House Intelligence Committee on Tuesday, Mr Brennan said he became increasingly concerned that United States President Donald Trump's associates were being manipulated by Russian intelligence services as part of a broader covert influence campaign that sought to disrupt the election and deliver the presidency to Mr Trump.
"I was worried by a number of the contacts the Russians had with US persons," Mr Brennan said, adding that he did not see proof of collusion before he left office on Jan 20, but "felt as though the FBI investigation was certainly well founded and needed to look into those issues".
Mr Brennan's remarks represent the most detailed public accounting to date of his tenure as CIA director during the alleged Russian assault on the United States presidential race, and the agency's role in triggering an FBI probe that Mr Trump has sought to contain.
"It should be clear to everyone that Russia brazenly interfered in the 2016 presidential election process," Mr Brennan said at one point, one of several moments in which his words seemed aimed squarely at the President.
Mr Trump has refused to fully accept the unanimous conclusion of US intelligence agencies that Russia stole thousands of sensitive e-mails, orchestrated online dumps of damaging information and employed fake news and other means to upend last year's race.
Republican lawmakers spent much of Tuesday's hearing trying to get Mr Brennan to concede that he had no conclusive evidence of collusion between the Trump campaign and Moscow.
Mr Brennan acknowledged that he still had "unresolved questions" about the purpose of those contacts when he stepped down as CIA director in January. "(But) I know what the Russians try to do," Mr Brennan said. "They try to suborn individuals and get individuals, including US persons, to act on their behalf either wittingly or unwittingly."
Mr Brennan refused to name any of the US individuals who were apparently detected communicating with Russian officials.
The FBI investigation, which began last July, has scrutinised Mr Trump's associates, including Mr Paul Manafort, Mr Trump's former campaign manager; Mr Carter Page, who was once listed as a foreign policy adviser to Mr Trump; and former national security adviser Michael Flynn, who was forced to resign after misleading statements about his contacts with the Russian ambassador were exposed.
The probe has intensified in recent weeks and identified a current White House official as a significant person of interest. Because Russia uses intermediaries and other measures to disguise its hand, "many times, (US individuals) do not know that the person they are interacting with is a Russian", Mr Brennan said.
He added that Russian agencies routinely seek to gather compromising information to coerce treason from US officials who "do not realise they are on that path until it gets too late".
The remark appeared to be in reference to Mr Flynn.
The Senate Intelligence Committee is issuing two new subpoenas for information from Mr Flynn's companies and challenging his lawyer's refusal to comply with an existing subpoena for documents detailing his contacts with Russian officials, committee leaders announced on Tuesday.