Mr Downer passed on the information to both the US ambassador in the UK and the Australian government via diplomatic cable after a meeting during which Mr Trump's foreign policy adviser, George Papadopolous, told him the Russians had a dirt file on Democratic presidential candidate Hillary Clinton.

In May, after Mr Trump had publicly raised Australia's involvement in sparking the Russia probe, US Ambassador Joe Hockey pledged co-operation in a letter sent to Mr Barr and Mr Trump's acting chief of staff, Michael Mulvaney.

"The Australian government will use its best endeavours to support your efforts in this matter," Mr Hockey wrote.

"While Australia's former High Commissioner to the United Kingdom, the Hon Alexander Downer, is no longer employed by the government, we stand ready to provide you with all relevant information to support your inquiries."

A government source said Mr Morrison explained to Mr Trump that Mr Downer had simply passed on information in his capacity as a diplomat and nothing more.

But Labor is demanding a public statement from Mr Morrison and has even called on the White House to release the transcript of the phone call in early September in which Mr Trump put the weights on the Prime Minister.

"I think Scott Morrison needs to be very clear about the circumstances around this phone call, what was said and whether any agreement was reached in terms of assistance," Labor leader Anthony Albanese said.


Former Labor leader Bill Shorten said Mr Morrison risked being perceived as Mr Trump's lapdog.

"Prime Minister Morrison got a very warm, indeed special reception from President Trump," he said.

"Mr Morrison needs to clean up the perception that perhaps the special reception was returned for special favours done."

Mr Downer said on Tuesday his role was simply to pass on what Mr Papadopolous told him. He also said he was unaware Mr Trump had raised the matter with Mr Morrison.

"I had a conversation with this guy and I passed on one element of the conversation to the Americans. There's just nothing more to it," Mr Downer said.

"I know nothing about conversations that Scott Morrison has had with the Americans, including President Trump, about this."

The departments of Foreign Affairs, Home Affairs and the Attorney-General declined to say whether they have subsequently been contacted by the Americans.


The request by Mr Trump has embroiled Australia in the impeachment scandal surrounding the President after he enlisted the Ukrainians to try to damage potential presidential rival Joe Biden.

It "shows the extent to which Mr Trump sees the attorney-general as a critical partner in his goal to show that the Mueller investigation had corrupt and partisan origins," The New York Times reported.

It also shows "the extent that Mr Trump sees the Justice Department inquiry as a potential way to gain leverage over America’s closest allies.

"And like the call with the Ukrainian President, Volodymyr Zelensky, the discussion with Mr Morrison shows the President using high-level diplomacy to advance his personal political interests."