The ambassador to the United States Joe Hockey personally steered Australia's dealings with the FBI on explosive revelations of Russian hacking during last year's presidential campaign in a sign of how politically sensitive the Australian government regarded the bombshell discovery, Fairfax Media understands.

It is also understood there is now annoyance and frustration in Canberra that the High Commissioner to Britain Alexander Downer has been outed through leaks by US officials as the source of information that played a role in sparking an FBI probe into the Trump campaign's dealings with Moscow.

Fairfax Media has confirmed independently that the conversation first reported by The New York Times took place. In May 2016, Trump campaign adviser George Papadopoulos told Mr Downer over drinks at an upscale London wine bar that the Russians had a dirt file on rival candidate Hillary Clinton in the form of hacked Democratic Party emails.

Mr Downer conveyed the conversation to Canberra via an official cable, though apparently not immediately – perhaps because he did not take the 28-year-old adviser's claims altogether seriously until the hacked emails were released by Wikileaks in late July.