The 31-year-old from Chicago is keen for a coffee, but the barista is AWOL.

Trump's "coffee boy" can't get a coffee.

"George, why don't you jump over the counter and make us a couple of caramel macchiatos," I suggest.

We laugh.

Papadopoulos picked up the 'coffee boy' title after he became one of Trump's first associates to be swept up by Special Counsel Robert Mueller's probe into Russian collusion.

He entered a guilty plea to lying to the FBI and was sentenced to 14 days' prison.

Trump quickly gave Papadopoulos the flick, describing him as a "young, low-level volunteer".

Former Trump campaign adviser Michael Caputo piled on around the same time with the coffee boy tag.

"You might have called him a foreign policy analyst, but if he was going to wear a wire, all we would have known now is whether he prefers a caramel macchiato over a regular American coffee," Caputo told CNN.

Papadopoulos' decision to have a drink with one of Australia's most well-known politicians-turned diplomats, Alexander Downer, on a rainy May 10, 2016 evening in London has made Papadopoulos a potentially significant figure in Australian political history.

In the aftermath of the Robert Mueller probe finding no evidence of collusion between Russia and the Trump campaign, the president and his Republican Party are now determined to discover why the FBI launched a counterintelligence investigation just months before Trump's election win.

That rainy night meeting with Downer at the Kensington Wine Rooms is expected to be put under the microscope.

"There is still this misunderstanding that Alexander Downer and I randomly met at a bar in London and he was drunk, I was drunk and we were apparently discussing conspiracy stuff," Papadopoulos tells AAP.

"There is nothing further from the truth."

Papadopoulos claims Downer, then Australian high commissioner to the UK, and another Australian official, Erika Thompson, set up that bar meeting to spy on him.

"I believe Australian and UK intelligence were involved in an active operation to target Trump and his associates," Papadopoulos says.

Downer has previously denied 'spying' on Papadopoulous when they meet and had drinks.

The Department of Foreign Affairs and Trade also dismissed the claim.

"The Australian government categorically rejects any allegation that it sought somehow to interfere in the US presidential election," a DFAT spokesperson said.

Papadopoulos' claims seem like Hollywood spy thriller fantasy but he makes an interesting case in his just released book, Deep State Target.

It details his journey from an unknown energy analyst to an unpaid foreign aide on the Trump campaign, the meeting with Downer, being grilled by the FBI, arrested at Washington DC's Dulles Airport, prosecuted by Mueller and sentenced to 14 days' prison in a facility in Wisconsin dubbed Camp Cupcake.

Along the way he met mysterious Maltese academic Joseph Mifsud, a Russian woman dubbed "Vladimir Putin's niece", American academic Stefan Halper who Papadopoulos describes as "The Walrus" and a sexy Cambridge University research assistant with a "classic honey-pot act".

Papadopoulos headlines his chapter on Downer with "The Devil From Down Under" and describes him as "a stretched-out, grey-haired version of New Wave pop star Elvis Costello" and "oozing aggression".

The drinks became infamous because Downer claimed Papadopoulos told him, over just one gin and tonic each, Russia might use "damaging" material they had on Trump presidential rival Hillary Clinton in the lead-up to the election.

Downer says he sent the information back to Canberra.

Weeks later when Russian hacking of the Democratic National Committee was discovered the information apparently became a potentially significant lead.

Papadopoulos denies telling Downer about the Russian information, but he does not deny the knowledge.

Papadopoulos says Mifsud told him on April 26 - a couple of weeks before meeting Downer - that Russia had "thousands" of Clinton's emails and Papadopoulos admits telling the Greek Foreign Minister Nikolaos Kotzias about it 16 days after the Downer drinks.

"I never told Downer anything about hacked emails," Papadopoulos said.

"I'm confident I never said that."

Papadopoulos believes Downer recorded their conversation with a phone during the brief meeting at the Kensington Wine Rooms. This claim has not been independently substantiated.

"The phone comes out again," Papadopoulos writes in the book.

"He must have grabbed it and held it up at least four times.

"He is so aggressive, so hostile, it's actually a bit intimidating."

AAP has sought comment from Downer, who works for a think tank in the UK, and is awaiting a response.

Australian Associated Press