NBC News is reporting that two U.S. officials with direct knowledge told the news organization on Tuesday that briefing materials prepared for President-elect Donald Trump included information that initially circulated among Trump opponents and was passed to U.S. intelligence agencies making damaging allegations about his dealings with Russians.

However, neither of the officials could confirm that the FBI was actively investigating the information, which has not been verified by U.S. agencies.

The sources would not comment on the nature of the allegations. The Trump transition team did not immediately respond to a request for comment.

But Trump himself did tweet at 8:19 p.m. ET Tuesday, in all caps, “FAKE NEWS — A TOTAL POLITICAL WITCH HUNT!”

Appearing Tuesday evening on NBC’s “Late Night with Seth Meyers,” Trump adviser Kellyanne Conway dismissed the reports as having possibly originated with a Russian investigator or groups that wanted Hillary Clinton to win the election.

You can get the rest of this story at NBC News or watch the video above.