An explosive but unsubstantiated political research dossier on Donald Trump's links to Russia alleges that his aides colluded with the Kremlin ahead of the US election, and that Russia has compromising information of a sexual nature about Trump.
American media and politicians have been in possession of versions of the 35-page report for months but, unable to corroborate its claims, had declined to publish it.
On Tuesday, after several media reported that Trump had been briefed on the allegations circulating about him, BuzzFeed news took the controversial step of publishing the dossier in full — while admitting it is "unverified."
Here is what we know:
What is the Russia dossier?
The 35 pages consist of memos compiled before and after the November 8 election by a former British spy, hired to produce opposition research on the Trump campaign, first by a Republican rival of Trump and then later by people tied to Hillary Clinton's Democratic campaign.
On Friday US intelligence chiefs, briefing Trump on allegations of Russian interference in the election, reportedly included a two-page summary of the most credible claims from the dossier.
That classified summary has been shown only to Trump, President Barack Obama, and a group of senators from the Senate Intelligence Committee.
The dossier's author was identified by the Wall Street Journal as former MI6 officer Christopher Steele, now the director of British consultancy Orbis Business Intelligence.
Britain's Daily Telegraph reported that Steele, 52, had fled his home near London, fearing for his safety after his name was made public.
What claims does it make?
The dossier includes unsubstantiated claims that Russians possess videos involving prostitutes, filmed during a 2013 visit by Trump to a luxury Moscow hotel for the Miss Universe contest, supposedly as a potential means for blackmail.
It also alleges that Trump advisers, including his lawyer Michael Cohen, maintained regular contact with Russian officials and others linked to Russian intelligence during the election and have been exchanging information for "at least" eight years.
The former British spy behind the report, who had long experience in Russia, based it on what he heard from his contacts.
It is not known if any of the claims in the memos are true but US intelligence reportedly considered some of the allegations sufficiently credible for Trump to need to be informed.
The FBI has been investigating the claims and Democrats are demanding an inquiry into allegations Trump's team met with Russian officials during the campaign.
How has Trump responded?
Trump angrily dismissed the report as a fabrication, telling a news conference: "It's all fake news. It's phony stuff. It didn't happen."
And he slammed US intelligence for allowing the information to leak.
"I think it was disgraceful — disgraceful that the intelligence agencies allowed any information that turned out to be so false and fake out," Trump charged. "I say that that's something that Nazi Germany would have done."
Trump's lawyer Cohen — who was alleged to have met Russian operatives in the Czech capital in August — meanwhile denied having ever visited Russia or Prague.
What are Trump's known ties to Russia?
Trump reiterated at Wednesday's news conference that he has "no loans, no dealings, and no current pending deals" with Russia, when asked if the country could have any leverage over him.
Several Trump advisors have longstanding links to the country, however.
Paul Manafort, his first campaign manager, was previously a consultant to Moscow-backed former Ukraine prime minister Viktor Yanukovych, and also worked with Russian oligarchs with Putin ties.
Another Trump advisor, Carter Page, was previously a Moscow-based investment banker and visited Moscow in July and then in December after the election for what he called private affairs.
Trump's nominee for National Security Adviser, Michael Flynn, was paid by Russian broadcaster RT to join a gala celebration in Moscow last year, where he sat at a banquet table with President Vladimir Putin.
The president-elect himself has a long history of seeking closer links with Russia. He sought since the 1990s to build a luxury apartment and hotel building in Moscow, but has never been able to seal a deal.
When visiting Moscow in 2013 for the Miss Universe contest, Trump said he hoped to build bonds with Putin. He did not meet the Russian strongman, but did meet a top Putin aide.
Court documents also show that Russian investment helped fund a major Trump-backed New York building, the 46 floor Trump Soho luxury apartment development built in the mid-2000s.