Shortly after reports surfaced in the media Tuesday that Russian operatives have compromising personal and financial information on Donald Trump, the president-elect tweeted "FAKE NEWS!"
Trump's full tweet read "FAKE NEWS - A TOTAL POLITICAL WITCH HUNT!" He previously has denied that Moscow had any influence in the election, while defending closer ties with that country.
The reports said Trump was told last week by the heads of domestic intelligence agencies that Russian operatives claimed to have the information.
Trump was given a two-page synopsis of the information last Friday, when he also was given a classified briefing on alleged Russian interference in the U.S. presidential election, according to the reports, which cited unnamed sources who had knowledge of the briefing.
President Barack Obama was given the information on Thursday.
CNN, which first reported the story Tuesday, did not give details of the so-called compromising information.
That information had been known since late last year among some journalists and politicians in Washington, the media reports suggested.
Several media have reported on the intelligence report, but the information has not been corroborated.
The allegations against Trump came, in part, from memos compiled by a former British intelligence agent with extensive Russian contacts, and whose previous work for the U.S. has been considered credible, according to media reports.
The FBI was given the information in August, months before the November election, CNN reported.
"What has changed since then is that U.S. intelligence agencies have now checked out the former British intelligence operative and his vast network throughout Europe and find him and his sources to be credible enough to include some of the information in the presentations" to Trump, CNN said.
FBI Director James Comey, who was testifying at a Senate hearing regarding Russian election hacking Tuesday, refused to say whether his bureau is investigating any possible ties between Russia and the Trump presidential campaign, citing policy not to comment on what the bureau might be doing.
In late October, Comey angered Democrats when he announced 11 days before the election that the FBI was looking at more emails as part of its investigation of Hillary Clinton, who then lost the presidential election to Trump.
The rumors were seemingly supported when former U.S. Senate Minority Leader Harry Reid directed a letter to Comey regarding the Clinton investigation.
In the letter, he said, "It has become clear that you possess explosive information about close ties and coordination between Donald Trump, his top advisors and the Russian government -- a foreign interest openly hostile to the United States, which Trump praises at every opportunity. The public has a right to know this information."
The Trump campaign had yet to respond to the media reports. But he previously has denied that Moscow had any influence in the election, while defending closer ties with that country.
U.S. intelligence agency chiefs last week testified to the Senate that Russian President Vladimir Putin ordered an operation to meddle with the U.S. election with the aim of hurting Clinton's campaign and boosting that of Trump.