In an interview on Radio National,she noted that “the report saying that[there could have been a lab leak] that is contested within the US intelligence community,” but repeated calls for more investigation of the origins of coronavirus.

“We’ve been consistent about the need to identify the origins to ensure that a pandemic doesn’t happen again and to ensure that we’re all better prepared.”

White House press secretary Jen Psaki said a day earlier that the White House supported a new World Health Organisation investigation in China,but added it “would require China finally stepping up and allowing access needed to determine the origins”.

Biden,for his part,held out the possibility that a firm conclusion may never be known,given the Chinese government’s refusal to fully co-operate with international investigations.

“The failure to get our inspectors on the ground in those early months will always hamper any investigation into the origin of COVID-19,” he added.

In another sign of shifting attitudes,the Senate approved two Wuhan lab-related amendments without opposition,attaching them to a largely unrelated bill to increase US investments in innovation.

One of the amendments,from Republican Senator Rand Paul,would block US funding of Chinese “gain of function” research on enhancing the severity or transmissibility of a virus.

The other amendment was from Republican Senator Joni Ernst and it would prevent any funding to the Wuhan Institute of Virology.

Both were approved without roll call votes as part of the broader bill that is still under debate in the Senate.

Many proponents of lab leak theory reject the more extreme hypothesis that the virus could have been deliberately released by the Chinese government after it was manufactured for bio-warfare.

Republican congressman Mike GallaghertoldThe Age and the Sydney Morning Herald that when Senate colleague Tom Cotton called for the lab leak theory to be investigated last year “the American media basically all went out in force and called him a tin foil hat wearing conspiracy theorist”.

“Now we know there’s a decent amount of evidence stacking up for the lab leak hypothesis,” Gallagher says.

“In the last few weeks it seems like the dam is breaking - and not just among Republican politicians like me. Scientists and the media are now taking it seriously.”

Momentum for the lab leak theory has only grown following the release in March of the World Health Organisation draft report which found it “extremely unlikely” the virus emerged as a result of a laboratory-related accident.

WHO boss Tedros Adhanom Ghebreyesus called for more investigation into the lab leak theory,saying that “it did not receive the same depth of attention and work as the other hypotheses”.

Administration officials continue to harbor strong doubts about the lab leak theory. Rather,they view China’s refusal to cooperate in the investigation — particularly on something of such magnitude — as emblematic of other irresponsible actions on the world stage.

Privately,administration officials say the end result,if ever known,won’t change anything,but note China’s stonewalling is now on display for the world to see.

Dr Francis Collins,the National Institutes of Health director,criticised the WHO report when he appeared before the Senate on Wednesday (Thursday AEST).

“It is most likely that this is a virus that arose naturally. But we cannot exclude the possibility of some kind of a lab accident. That’s why we’ve advocated very strongly that WHO needs to go back and try again after the first phase of their investigation really satisfied nobody. And this time we need a really expert driven,no-holds-barred collection of information,which is how we’re mostly really going to find out what happened.”

Infectious disease expert Dr Anthony Fauci told the Senate the virus was “most likely” naturally occurring. “But no one knows that 100 per cent for sure. And since there’s a lot of concern,a lot of speculation,and since no one absolutely knows that,I believe we do need the kind of investigation where there’s open transparency.”

The State Department,which ended one Trump-era probe into the Chinese lab theory this spring,said it was continuing to cooperate with other government agencies and pressed China to cooperate with the world.

“China’s position that their part in this investigation is complete is disappointing and at odds with the rest of the international community that is working collaboratively across the board to bring an end to this pandemic and improve global health security,” said spokesman Ned Price.

AP,agencies,with Matthew Knott