The former MI6 agent who collated the dossier on US president-elect Donald Trump reportedly felt "duty bound" to share the intelligence he "deemed crucial".
Christopher Steele, the former British intelligence agent behind allegations regarding the president-elect, even worked without pay because of his concerns of what he was uncovering, according to a report.
The in-hiding 52-year-old made allegations, unsubstantiated by the press and security services, of Moscow holding lurid and incriminating material on Mr Trump and of having links with his campaign team.
Mr Steele revealed his findings to David Corn, a journalist from magazine Mother Jones, who first reported on the dossier's existence in Autumn last year.
Mr Corn, without identifying his source, backed him up on Friday, saying the spy was "confident" about his material which he was "genuinely concerned" about its implications, despite it being a work in progress.
"He came across as a serious and sombre professional who was not eager to talk to a journalist or cause a public splash. He realised he was taking a risk, but he seemed duty bound to share information he deemed crucial," he added.
The Independent reported that Mr Steele worked without pay towards the end of his investigation into Mr Trump's alleged Kremlin links because he of his severe concerns.
Mr Steele is said to have originally compiled the dossier on Mr Trump for his Republican opponents before continuing his work for the Democrats.
He then relayed his discoveries to British and American intelligence services because he deemed the information to be a matter of national security for both nations, the website reported.
Mr Trump, who is due to take office on Friday, denied the allegations the dossier by Mr Steele, who runs London-based Orbis Business Intelligence Service.
After initially blaming US intelligence services, the controversial tycoon tweeted: "It now turns out that the phony allegations against me were put together by my political opponents and a failed spy afraid of being suede.
"Totally made up facts by sleazebag political operatives, both Democrats and Republicans - FAKE NEWS! Russia says nothing exists.
"Probably released by 'Intelligence' even knowing there is no proof, and never will be. My people will have a full report on hacking within 90 days!"