It was a chance romantic encounter by George Papadopoulos that set in train the events that led to the Australian government tipping off Washington about what it knew of Russian hacking efforts to swing the US presidential election.
Fairfax Media can reveal a woman in London with whom Papadopoulos became involved happened to know Alexander Downer and told the Australian High Commissioner about Papadopoulos, a newly signed staffer for Donald Trump. Downer, being a canny diplomat, followed it up and arranged a meeting with the young American, who was mostly living in London at the time.
What followed was the now infamous May 2016 conversation over many glasses of wine at the swanky Kensington Wine Rooms, during which the 28-year-old Papadopoulos spilled to Downer that he knew of a Russian dirt file on the rival Clinton campaign consisting of thousands of hacked emails.
That night was a key moment that helped spark the FBI probe - since taken over by respected former FBI director Robert Mueller as a special counsel - into possible Trump campaign collusion with the Kremlin, including its hacking of the Democratic National Committee.
As former US director of national intelligence James Clapper told CNN this week: "I think it was probably one of several stimulants for the investigation but was not the only factor."
It is almost certain Downer has since been interviewed or at least debriefed by Mueller's team.
As remarkable as it seems that Papadopoulos would be so reckless as to tell Downer - a foreign diplomat he'd just met - that he knew about the Russian hacking, Downer is known for his fondness for expansive conversation over wine, so it is plausible Downer had the young man talking well past the point at which he should have stopped.
The romantic link explains that it was a random connection of Papadopoulos to Australia's High Commission that sparked the meeting. One unanswered question is whether Papadopoulos had boasted to the woman of his Russian connections and this was a subject of interest to Downer. But Trump was the presumptive Republican nominee by the start of May 2016, so Downer would have seen value in meeting with one of his campaign team anyway.
Downer, insiders agree, was doing his job, though it's understood he didn't send an official cable to Canberra reporting the conversation until July after Wikileaks published the hacked emails.
Canberra then shared the conversation with Washington. It was well aware it was in the fraught position of telling authorities under a Democratic administration that a staffer from the Republican nominee's campaign had foreknowledge of the Russian hacking. But most experts have said the government did the right thing and is unlikely to have damaged the relationship with the now-Trump administration.
"Alexander was doing what a High Commissioner should do, finding pathways into the campaign team," said Peter Jennings, executive director of the Australian Strategic Policy Institute.
"He professionally reported it back to head office. If you had what seemed to be reasonable information about the possibility of collusion, you would want to tell American internal intelligence appropriately. What seems to have happened is we've done the right thing."
It is understood that Australia's ambassador to Washington, Joe Hockey, talked to the FBI as part of managing the information flow.
Some close observers have pointed out that Canberra wasn't informing on Papadopoulos as such but simply passing on to an ally useful information about Russia's hacking. By late July 2016, US intelligence had reportedly "high confidence" Russia was behind the Democrats hack, but it wasn't until October that it publicly said it was certain.
A spokesperson for the Department of Foreign Affairs declined to comment, citing an ongoing investigation.
Papadopoulos declined to comment, referring Fairfax Media to his lawyers, who did not respond by deadline.
Papadopoulos has since pleaded guilty to lying to the FBI. In his January interview, he didn't deny knowing Joseph Mifsud, a mysterious Maltese professor with links to the Russian government, nor having met with Russian officials to whom Mifsud introduced him. Nor did he deny that Mifsud had told him the Russians had "dirt" on Hillary Clinton in the form of "thousands of emails".
But he falsely claimed all this happened before he joined the campaign team, downplaying any suggestions of collusion. These calculated denials - revolving around the timing, not the fact of his knowledge - suggest Papadopoulos guessed someone had already told the FBI he had been boasting of his knowledge of the emails.
Mr Jennings said that while there were likely multiple starting points for the Mueller probe, the Downer conversation could explain why the FBI zeroed in on Papadopoulos.
"We can now say we played a part."
