Russia cultivated Donald Trump for years before the 2016 election and holds compromising material on the President-elect, according to a series of explosive but unconfirmed memos made public today.
The memos, produced by a British intelligence operative, contain extensive details of efforts by Russia's intelligence community, directed by Russian President Vladimir Putin, to sway the outcome of the US election.
A source told the operative that Mr Trump's "unorthodox behaviour in Russia over the years had provided the authorities there with enough embarrassing material on the [then] Republican presidential candidate to be able to blackmail him if they so wished."
The British memos, which had circulated through US political circles since before the election, contained details about extensive contact between Mr Trump and Russia in the lead-up to the campaign.
The inclusion of information from the British memo in a US briefing to Mr Trump by intelligence chiefs last week suggests that US authorities are now gaining confidence in the source, who is understood to be outside an official agency.
Mr Trump, without referring to the story, tweeted that it was "fake news" and repeated his claim, echoed in Moscow, that the reports of his collaboration with Russia were simply "A TOTAL POLITICAL WITCH HUNT."
The memos were prepared mainly by a retired British intelligence operative for a Washington political and corporate research firm, according to The New York Times. The firm was paid for its work first by Trump's Republican rivals and later by supporters of his Democrat rival, Hillary Clinton.
The newspaper said it had checked on a number of the details included in the memos but had been unable to substantiate them.
BuzzFeed published the series of memos in full, "so that Americans can make up their own minds about allegations" although the editor-in-chief of the outlet stressed that it couldn't verify them.
The outlet also said the memo "is not just unconfirmed: it includes some clear errors".
According to the memos, Mr Putin's goal in cultivating Mr Trump was to "sow discord and disunity both within the US itself, but more especially within the Transatlantic alliance which was viewed as inimical to Russia's interests".
WikiLeaks served a role too, the memos said.
An associate of Mr Trump told the British operative that the Kremlin was behind the appearance of Democratic National Committee emails on WikiLeaks "as a means of maintaining plausible deniability".
There was also an "agreed exchange of information established" between the Trump camp and Moscow, with Mr Trump's team using moles within the Democratic National Committee and hackers based in the US and Russia.
"Putin [was] motivated by fear and hatred of Hillary Clinton," the memos said.
Among the compromising material - or "kompromat" - that Russian authorities had obtained on Mr Trump was a claim that he hired prostitutes to perform a sex act in the presidential suite of the Ritz-Carlton hotel in Moscow where President Barack Obama and his wife, Michelle, had stayed during an official trip to Russia.
"The hotel was known to be under FSB [Russian secret service] control with microphones and concealed cameras in all the main rooms to record anything they wanted to."
The event was believed to have happened in 2013, the British operative's memo said. Mr Obama visited Russia in 2009 and 2013. Nonetheless, the authenticity of the documents remained in doubt.
Throughout the US election campaign, Mr Trump, who sits at the centre of a family real estate empire, refused to release his tax returns, breaking a long-standing tradition in US politics. Questions over his finances have continued to mount.
At a 2008 real estate conference, the President-elect's son Donald Trump jnr was quoted as saying: "Russians make up a pretty disproportionate cross-section of a lot of our assets.
"We see a lot of money pouring in from Russia."
However, details of money Mr Trump owes or is owed by foreign entities remain scant.
The issue of foreign influence on a US president has alarmed some of political class in the US, while many of Trump's voters are less concerned.
The story Russia planned to cultivate and compromise Donald Trump, according to leaked memos first appeared on The Sydney Morning Herald.