Australia's longest serving foreign minister says not since the Cold War has he seen an ambassador behave as "recklessly" as China's ambassador to Australia did this week.

The Federal Government has described Ambassador Jingye Cheng's comments in an interview with the Australian Financial Review as "threats of economic coercion".

Mr Cheng suggested the Chinese public may boycott Australian products or decide not to visit Australia in the future if the Government continued its push for an inquiry into the origins of COVID-19.

"If the mood is going from bad to worse, people would think 'Why should we go to such a country that is not so friendly to China?'," he told the paper.

"Maybe the ordinary people will say 'why should we drink Australian wine? Eat Australian beef?'"

Alexander Downer described a boycott of Australia as "completely absurd". ( Getty: Tracey Nearmy )

Former foreign minister Alexander Downer says the ambassador's conduct is almost unprecedented.

"Not since the days of the Soviet Union have I seen an ambassador behave in such a reckless, undiplomatic way. And what is the problem? I mean the Prime Minister has just said that there should be an investigation," he told ABC RN's Between The Lines.

"The Chinese ambassador's reaction is as though China has been cornered and told that it's guilty.

"We're not going to be bullied by an ambassador who's gone rogue in Canberra."

He says while China can "of course decide that they don't want to import anything from anywhere around the world", that would hurt an economy already suffering as a result of the coronavirus crisis.

"I mean it's just a completely absurd proposition," Mr Downer said.

Mr Downer says there must be an impartial investigation into the cause of the outbreak.

"The global economy has been brought to a halt, 200,000 people are dead as a result of it," he said.

"We've got to investigate it. And we've got to find out how it happened. And I'm very surprised that the Chinese should be so resistant to getting to the heart of what happened."

Unlike current Foreign Minister Marise Payne, Mr Downer says the WHO should lead the probe.

"It should be led by the World Health Organization, it should include epidemiologists and other scientists from a variety of different countries, including but not exclusively Western countries and obviously people from China," he says.

"It should be wide-ranging, it needs to try to establish how this happened. Not to investigate the behaviour of the Chinese government, I don't think that is going to be very politic, but to investigate how this virus broke out.

"That is what we need to investigate and that's what we need to understand. So we never see it happen again."

Government MPs pile on ambassador

Mr Downer's comments come amid growing criticism of Mr Cheng from within Government ranks, with two Federal backbenchers hitting out at the ambassador on Thursday afternoon.

In some of the harshest remarks from the Government thus far, Liberal MP Trent Zimmerman labelled Mr Cheng's intervention "downright despicable".

"I thought the ambassador's comments were downright despicable and menacing," he said.

"But in the broader framework we should have a relationship with China that allows us to be raising these issues whilst also recognising that China will always be an important partner for us."

His comments came as former Turnbull government minister Concetta Fierravanti-Wells criticised the appearance of the Victorian Chinese Consul General at a coronavirus testing announcement at the invitation of businessman Andrew Forrest, alongside Health Minister Greg Hunt.

"It was unfortunate, I don't think we should have afforded that opportunity and it did put Minister Hunt in a very difficult position," she said.

"This is what the communist regime is doing all over the world. We have seen that the regime in Beijing is desperately trying to re-establish a degree of credibility after the virus has happened, they are desperately trying to deflect the origins of the virus."

China 'flatly rejects' Australian concerns

In a statement released on Tuesday by China's Embassy, Mr Cheng said he "flatly rejected the concern expressed from the Australian side over his remarks".

It said he "called on Australia to put aside ideological bias, stop political games and do more thing to promote the bilateral relations".

That same day Trade Minister Simon Birmingham said the Government would continue to push for an investigation.

"Australia is no more going to change our policy position on a major public health issue because of economic coercion or threats of coercion, than we would change our policy position in matters of national security," he said.

Mr Downer says he believes Australia's economic relationship with China will largely return to "business as usual".

"It's in China's interest that they import the raw materials that drive the Chinese economy from Australia," he said.

"Of course they can decide they don't want to import them from Australia, [but] where else are they going to get them from and at what price?

"It's not as though China has all that many choices so I think largely things will return to as they were."