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.