A ROMANTIC encounter triggered Australia’s role in the FBI probe into Russian hacking during the US election, it has been revealed.

Australia’s outgoing High Commissioner to Britain, Alexander Downer, who played a part in sparking the FBI investigation, was reportedly friends with a London woman who had became involved with George Papadopoulos, a new Donald Trump staffer.

Fairfax Media reports Downer arranged a meeting with Papadopoulos, an American man based in London, in May 2016, which would eventually become a bombshell conversation between the pair where the Trump staffer let slip he knew of a Russian “dirt file” on the Clinton campaign consisting of thousands of hacked emails.

The revelations would lead to a massive FBI probe into the US election, which is now headed by former FBI director Robert Mueller as a special counsel.

If allegations are true, it would mean one side of US politics was colluding with a foreign power, the Kremlin, to undermine another political party.

Former US director of national intelligence James Clapper told CNN this week that the conversation was “probably one of several stimulants for the investigation,” but added it was not the only factor.

It’s understood Downer didn’t send an official report to Canberra reporting the conversation until July after the hacked emails of Trump’s rival Democratic candidate Hillary Clinton were released by WikiLeaks.

Canberra then shared the information with Washington.

Australia’s ambassador to Washington, Joe Hockey, talked to the FBI as part of managing the information flow, it is understood.

Papadopoulos has since pleaded guilty to lying to the FBI about his Kremlin-related contacts, and more specifically on a Moscow-linked professor who was offering “dirt” on Clinton.

Prime Minister Malcolm Turnbull has repeatedly declined to comment on Mr Downer’s involvement in the probe.

It is understood he is visiting the US early this year.