Our latest investigation, carried out over more than six months and involving the examination of hundreds of articles across dozens of websites, found that the operation has a new target - American voters.

Dozens of bogus stories tracked by the BBC appear aimed at influencing US voters and sowing distrust ahead of November’s election. Some have been roundly ignored but others have been shared by influencers and members of the US Congress.

Another fake which went viral earlier this year was more directly aimed at American politics. It was published on a website called The Houston Post – one of dozens of sites with American-sounding names which are in reality run from Moscow - and alleged that the FBI illegally wiretapped Donald Trump’s Florida resort.

It played neatly into Trump’s allegations that the legal system is unfairly stacked against him, that there is a conspiracy to thwart his campaign, and that his opponents are using dirty tricks to undermine him. Mr Trump himself has accused the FBI of snooping on his conversations.

Experts say that the operation is just one part of a much larger ongoing effort, led from Moscow, to spread disinformation during the US election campaign.