(NPR) Top U.S. intelligence officials have briefed leaders in Washington about an explosive — but unverified — document that alleges collusion between Russia and President-elect Donald Trump, NPR has learned.

The brief, which NPR has seen but not independently verified, was given by Senate Armed Services Committee Chairman John McCain to FBI Director James Comey on Dec. 9. Details from it have been part of presentations by Comey and other intelligence leaders to Trump, President Obama and key leaders in Congress.

Click to continue reading. By Philip Ewing. Updated, Wednesday, Jan 3, 2018.