Downer, Papadopoulos, gin and the file

That's about the only thing Alexander Downer and George Papadopoulos agree on.

Downer, the former Australian high commissioner to the UK, and Papadopoulos, the former foreign policy adviser to Donald Trump and soon-to-be US federal prison inmate, have become key figures in the increasingly murky probe into Russian interference in the 2016 US presidential election.

Downer and Papadopoulos could have faded into the background last Friday when Papadopoulos became US Special Counsel Bob Mueller's latest scalp and pleaded guilty in a Washington DC court to lying to the FBI.

He was sentenced to 14 days' jail and will surrender to prison authorities at a yet-to-be announced date.

Instead of going quietly Papadopoulos, who says he wants to write a book and enter politics, embarked on a media blitz with interviews with the New York Times and CNN.

CNN turned their chat into a one hour "Special Report" titled "The Mysterious Case of George Papadopoulos".

It was a meeting between Downer and Papadopoulos at London bar the Kensington Wine Rooms in May 2016, that has been credited with sparking the FBI investigation into Russia election interference that then led to the Mueller probe.

The New York Times first exposed the meeting in a bombshell report late last year and described it as a "night of heavy drinking".

Downer and Papadopoulos disagree.

They claim it was a quiet one.

"I think I had a gin and tonic," Papadopoulos told the New York Times.

Downer agreed.

The former foreign affairs minister told The Australian earlier this year he had just one gin and tonic and it was a weak pour - just 25ml of gin.

This is where the drinking pals' stories hit a fork in the road.

Downer says Papadopoulos mentioned at the meeting "the Russians might use material that they have on Hillary Clinton in the lead-up to the election, which may be damaging".

Downer said he reported the highly-sensitive information back to Canberra "the following day or a day or two".

Papadopoulos' recollection is not so clear.

In his media interviews he does not deny it, but states he did not remember saying it.

Papadopoulos does not deny knowing about the potential Russian Clinton dirt file and admits telling Greece's foreign minister about it.

How the information travelled from Downer and eventually to the FBI and US intelligence services is also murky.

The New York Times, in a story titled "How the Russia Inquiry Began: A Campaign Aide, Drinks and Talk of Political Dirt", reported "Australian officials passed the information about Mr Papadopoulos to their American counterparts" two months after the meeting when leaked Democratic Party emails began appearing online.

The Australian newspaper, after interviewing Downer, told a different version.

It reported "within 48 hours Downer had sent an official cable about what he had heard to Canberra" and "after a period of time, Australia's ambassador to the US, Joe Hockey, passed the information on to Washington".

Wall Street Journal columnist Kimberley Strassel tells a different story.

Strassel, quoting a "diplomatic source", wrote "Mr Hockey neither transmitted any information to the FBI nor was approached by the US about the tip".

"Rather, it was Mr Downer who at some point decided to convey his information - to the US Embassy in London," Strassel wrote.

If that is correct, Downer's actions could be a breach of diplomatic protocol and adds fuel to theories about Papadopoulos being targeted by intelligence agencies.

Conspiracy theorists have questioned why Downer reached out to the little-known Papadopoulos in the first place.

"We didn't know anything about Trump and Russia and we had no particular focus on that," Downer, describing his meeting to The Australian, said.

"For us we were more interested in what Trump would do in Asia."

Papadopoulos says he was mystified why Downer set up the meeting.

"So for the Australian high commissioner to reach out to me out of the blue, considering I had no background whatsoever in the US-Australian relationship, I found it odd I have to say," Papadopoulos told CNN.

Papadopoulos added fuel to the theories by taking to Twitter the past 24 hours to question Downer's motives.

Papdopoulos' wife Simona on Tuesday posted a blurry photo of Downer sitting with Stefan Halper, the American foreign policy scholar and FBI source who also reached out to Papadopoulos in 2016.

"The notion that Downer randomly reached out to me just to have a gin and tonic is laughable," Papadopoulos wrote.

"Some organization or entity sent him to meet me."

Australian Associated Press