Donald Trump has claimed US intelligence chief James Clapper called him to "denounce" an explosive dossier alleging links with Russia, despite an official statement hours earlier that said no judgement had been reached on the document's reliability.

Mr Clapper spoke with the President-elect on Wednesday evening to discuss the dossier - believed to have been compiled by a former British spy - that claims to show Russian intelligence agencies have compromising material about Mr Trump.

In a statement released after their conversation the director of national intelligence said: “The IC [intelligence community] has not made any judgement that the information in this document is reliable, and we did not rely upon it in any way for our conclusions.”

But Mr Trump used his first tweet on Thursday morning - just a few hours later - to claim that the intelligence chief had instead rubbished the report.

The incoming president wrote: “James Clapper called me yesterday to denounce the false and fictitious report that was illegally circulated. Made up, phony facts. Too bad!”

A fresh row between the President-elect and America’s most senior intelligence officer threatens to drive a deeper wedge between the agencies and Mr Trump, who will be inaugurated on 20 January.

In his New York news conference, Mr Trump made clear that he suspected US intelligence agencies of releasing the 35-page dossier, saying it would be a "tremendous blot" on the agencies' reputation if they were shown to have leaked it.

He earlier said they should “never have allowed this fake news to ‘leak’ into the public” and compared the intelligence agencies to Nazi Germany.

US President-elect Donald Trump on recent allegations

Mr Clapper responded by denying intelligence responsibility in a statement released after the news conference, saying: “I expressed my profound dismay at the leaks that have been appearing in the press, and we both agreed that they are extremely corrosive and damaging to our national security.

“I emphasised that this document is not a US Intelligence Community product and that I do not believe the leaks came from within the IC.”

Senior aide to the incoming president Kellyanne Conway told NBC's Today programme that the President-elect was "very happy" to get Mr Clapper's call.

However, she did not say whether Mr Trump believes the intelligence chief’s suggestion that the document was produced by someone outside the intelligence community.

Director of National Intelligence James R. Clapper Jr (Getty) (Matt McClain/The Washington Post)

The dossier contains unproven information about coordination between Mr Trump's inner circle and Russians about hacking into Democratic accounts, as well as unproven claims about unusual sexual activities by Mr Trump.

In October, then-senator Harry Reid wrote to the FBI asking it to release what it knew about the property tycoon’s ties to Russia.

In a letter on 30 October Mr Reid said he learned of the information from FBI Director James Comey and other top national security officials.

A few weeks later Senator John McCain became aware of the allegations but decided it was impossible to verify them without a proper investigation, according to reports.