A former British intelligence officer behind the dossier containing explosive but unverified claims about Donald Trump has fled his home fearing for his life, a report says.

Christopher Steele, a former MI6 officer who now runs an intelligence-gathering firm in London, has been identified as the author of the document, which alleges that Russia had amassed compromising material about the US President-elect.

Mr Trump, in a news conference, denounced the 35-page dossier as "nonsense", "fake news" and "phoney stuff".

Mr Steele, 52, fears a backlash from Moscow now that his name has been made public, the Daily Telegraph said.

He is "terrified for his and his family's safety", an unspecified source close to Mr Steele was quoted as saying in the newspaper.


Trump on news organisations

According to the report, the former spy packed his bags, left his cat with a neighbour and fled his home in Surrey on Wednesday morning.

Mr Steele reportedly was a spy in Russia in the 1990s and has maintained several contacts there.

He serves as director of Orbis, a firm founded in 2009 by former British intelligence professionals.

According to its website, Orbis has a "global network" of experts and "prominent business figures".

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The dossier dominated a news conference by Mr Trump in New York on Wednesday, his first in six months.

He suggested spy agencies may have leaked the material and accused them of practices reminiscent of Nazi Germany.

The remark escalates tensions between Mr Trump and US intelligence agencies.

James Clapper, the director of National Intelligence, said he had spoken with Mr Trump about the dossier and told the President-elect that he did not believe the leaks come from the US intelligence community.

Former defence secretary Leon Panetta told CBS that US national security was at stake.

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Protecting America, he said, requires good intelligence and "demands a relationship of trust and unfortunately I think I see a relationship in which that trust doesn't exist right now".

About the dossier:

:: It was commissioned by a Washington firm on behalf of Mr Trump's political opponents

:: It looks at alleged ties between the Trump campaign and Russia, claiming the Kremlin cultivated and supported Mr Trump for at least five years, also feeding him intelligence on political rivals including Hillary Clinton

:: It claims Russia had gathered embarrassing allegations against Mr Trump during a visit to Moscow years ago that could be used to blackmail him

The claims in the dossier had been widely circulated in recent months among the Washington media and members of Congress, but they could not be verified.

In October, Mother Jones magazine reported that a former Western spy assigned to look into Mr Trump's Russian ties had presented his findings to the FBI.

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Both President Barack Obama and the President-elect have received a two-page summary outlining the claims made in the dossier. The summary was attached to an intelligence report into Russian hacking.

News that Mr Trump and Mr Obama had received these documents was broken by CNN, prompting an angry reaction from Mr Trump during his news conference.

On Tuesday night BuzzFeed published the full dossier - a controversial decision since the claims are unverified. The website defended the move saying Americans "can make up their own minds".

Sky News has not been able to verify the authenticity or veracity of the report and is unable to substantiate the claims made within it.

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