Late in July 2016, FBI Director James Comey told members of the Obama White House
and the Director of National Intelligence, James Clapper, that the FBI had opened
the "Crossfire Hurricane" investigation into Donald Trump's campaign for president.
John Brennan, who was in charge of the CIA, already knew because he was the one who had been giving the FBI information about the Trump campaign.
Brennan told Congress in May 2017: "I knew of intelligence and information about contacts between Russian officials and U.S.
people that made me worry about whether or not those people were working with the Russians, whether on purpose or by accident.
This was the basis for the FBI's investigation to find out if collusion—working together—had happened.