Mr Downer reported the conversation back to Canberra via diplomatic cable. Canberra passed the information on to Washington and it reportedly contributed to the beginning of the FBI probe into potential collusion between the Trump team and Moscow, which then morphed into the inquiry by special counsel Robert Mueller.
Mr Trump swung onto the offensive in the wake of the Mueller report’s release and with the request to investigate its origins, he appears to be endorsing a theory – being pushed by Mr Papadopoulos and in conservative US media including Fox News – that some US intelligence and FBI officials conspired with help from foreign partners to concoct the Russia allegations and undermine the Trump campaign and presidency.
Mr Downer, who was Australia’s high commissioner to Britain when he met Mr Papadopoulos – who went on to spend 12 days in jail for lying to the FBI – laughed off the theory that he had been sent to spy on the junior campaign aide.
“The FBI and the State Department know that’s not true … As if somebody would ring me up and say, ‘Will you go and spy on some clown called Papadopoulos who’s a volunteer from the Trump campaign?’
Mr Downer avoided directly criticising Mr Trump, saying: “I’m not against him.”
Mr Downer said the matter was “to do with American politics” and he was comfortable about that.
“They have to play their politics … He’s obviously very good at politics because he became the President.”
He added: “The more it’s investigated, the more it’ll be shown to be a complete beat-up. So they’re welcome to investigate. I don’t care.”
He dismissed suggestions that the Barr investigation could smear Australia either way, saying it could be “handled with consummate ease” by the Morrison government.
Michael Fullilove, executive director of the Lowy Institute, said even accounting for Mr Trump’s history of scepticism about traditional US alliances, it was “disturbing to see him try to drag the UK and Australia into America’s fevered conspiracy politics”.
“Australia is the United States’ most reliable ally,” he said. “We don’t interfere in American elections and we don’t deserve to be treated like this.”
David Wroe is defence and national security correspondent for The Sydney Morning Herald and The Age.