Update: WikiLeaks has fired back at the Guardian, tweeting: "Remember this day when the Guardian permitted a serial fabricator to totally destroy the paper's reputation. @WikiLeaks is willing to bet the Guardian a million dollars and its editor's head that Manafort never met Assange." 

The Guardian's report was written by Luke Harding and Dan Collyns, and was based exclusively on unnamed sources. 

Paul Manafort, Donald Trump's former campaign manager, held secret talks with Julian Assange inside the Ecuadorian embassy in London, right around the time he joined Trump's campaign, according to The Guardian, which as is now the norm in reports of this kind refers to unnamed "sources."

Sources have said Manafort went to see Assange in 2013, 2015 and in spring 2016 – during the period when he was made a key figure in Trump's push for the White House.

It is unclear why Manafort wanted to see Assange and what was discussed. But the last meeting is likely to come under scrutiny and could interest Robert Mueller, the special prosecutor who is investigating alleged collusion between the Trump campaign and Russia.

A well-placed source has told the Guardian that Manafort went to see Assange around March 2016. Months later WikiLeaks released a stash of Democratic emails stolen by Russian intelligence officers. -The Guardian