Top Australian officials reportedly “broke with protocol” to allow Alexander Downer to be interviewed by the FBI about Russian meddling in the US election.

A sensational New York Times report has alleged that Alexander Downer sat down for an interview with two FBI agents in London in 2016 to discuss potential Russian meddling in the US presidential election.

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The report described the interview as a break with diplomatic protocol which could damage Australia's recently repaired relationship with US President Donald Trump.

The New York Times previously reported late last year it was at a boozy night in May 2016, at London's Kensington Wine Rooms, that Mr Trump's then foreign policy adviser George Papadopoulos told Mr Downer Russia had dirt on Mr Trump's political rival Hillary Clinton.

"Within hours of opening an investigation into the Trump campaign's ties to Russia in the summer of 2016, the FBI dispatched a pair of agents to London on a mission so secretive that all but a handful of officials were kept in the dark," the New York Times reported on Wednesday.

"Their assignment, which has not been previously reported, was to meet the Australian ambassador, who had evidence that one of Donald J. Trump's advisers knew in advance about Russian election meddling.

"After tense deliberations between Washington and Canberra, top Australian officials broke with diplomatic protocol and allowed the ambassador, Alexander Downer, to sit for an FBI interview to describe his meeting with the campaign adviser, George Papadopoulos."

The FBI agents summarised "their highly unusual interview" and their report helped provide the foundation for a case that became the probe headed by special counsel Robert Mueller, who is investigating allegations of collusion between the Trump campaign and Russia.