Alexander Downer, Australia’s high commissioner to the United Kingdom, has been hailed by some as a hero for allegedly sparking an investigation that could doom Donald Trump, as key players on both sides of the Pacific remain tight-lipped on the explosive claims.

A report by The New York Times on Sunday that Mr Downer secured a damning admission from a Trump official is yet to be denied.

The information was reportedly passed to the US government, and was used to instigate Robert Mueller’s probe into Russian meddling in the 2016 US election.

According to the Times, Mr Downer was drinking with George Papadopoulos, a Trump campaign foreign policy advisor, in London in May 2016. Mr Downer, who reportedly held his liquor better, won an admission from Mr Papadopoulos that he knew Russia had “political dirt” on presidential candidate Hillary Clinton.

When leaked Democratic Party emails began appearing in public two months later, Australian officials allegedly passed Mr Downer’s intel to their US counterparts.

The revelation has important diplomatic implications, as Australia is a close ally of the US. It has been greeted with stony silence.

The New Daily approached the Department of Foreign Affairs and Trade for comment. “The Australian government will not be providing a comment as there is an ongoing investigation,” a spokesperson said.

Mr Downer and the Trump administration have also gone to ground.

As part of Mueller’s investigation, Mr Papadopoulos pleaded guilty to lying to the FBI about his contacts with Russian officials during the campaign. His is one of the biggest scalps claimed by the investigation so far, which makes Australia’s tip-off all the more crucial.

Court documents have revealed that in April 2016 Mr Papadopoulos met a Professor Joseph Mifsud in London to discuss the man’s claim to possess thousands of damaging emails relating to Mrs Clinton. This meeting was mere weeks before the drinking session with Mr Downer.

The Times reported that the meeting between the Australian high commisisoner and the Trump aide was arranged through Israeli connections. The newspaper’s sources were reportedly US and international officials.

The Twitter account of the Australian High Commission to the UK has been bombarded with messages, most of them positive, from US citizen praising Mr Downer’s role.

Mr Papadopoulos is now reportedly assisting the Mueller probe. He joins another former advisor, Michael Flynn, who has also pleaded guilty to lying to the FBI about communications he had with Russia.

Mr Trump was inaugurated as 45th US president in January this year. Just 24 days later, Flynn resigned for misleading US Vice President Mike Pence about his discussions with senior Russian diplomat Sergey Kislyak.

In May, Mr Trump fired FBI director James Comey, seemingly because Comey was stepping up the Trump-Russia probe, with Flynn playing the key role.

The slow-moving but thorough investigation appears to be one of the bigger threats to Trump’s presidency, even as some polls have his approval ratings at lower levels than any US president in history.

Mr Downer will finish up as High Commissioner to the UK in early 2018, to be replaced by another senior Liberal politician, George Brandis.