From Ruth Sherlock, of the Telegraph of London, reporting on a conversation she had with a former US intelligence source:

The former agent also urged me to follow the money. Not just the election, but Mr Trump’s whole career, he claimed, is wrapped up in questionable financing from Russia.”It’s like every part of his business is somehow tied up in it” he said.

Much has been written, including in this newspaper, about Bayrock, the property development firm that was building Trump SoHo, his towering building in New York and other projects.

A key principle in Bayrock was Felix Sater, a Russian convicted of helping to lead a massive mafia-linked Wall Street stock fraud scheme. (Mr Sater also attacked a man at a New York bar by stabbing him in the face with the broken stem of a Martini glass).

Two lawyers, Frederic Oberlander and Richard Lerner, who have spent much of their careers tracking Bayrock’s dealings, allege in court documents that Bayrock “for most of its existence it was substantially and covertly mob-owned and operated”. 

In a petition to the US Supreme Court they write that Mr Sater’s father, Michael Sheferofsky, worked for Semion Mogilevich, the Russian mafia boss allegedly described by the FBI as “the most dangerous mobster in the world”.

The company was based in Trump Tower, and, despite Mr Trump’s claims that he barely knows Mr Sater, there is much reporting to show the opposite.

David Johnston, an American journalist who has spent years looking into connections between Mr Trump and the mafia wrote in Politico during the election that no other candidate for the White House “has anything close to Trump’s record of repeated social and business dealings with mobsters, swindlers, and other crooks“.