Dr Anthony Fauci (Image: EPA/Sarah Silbiger)

The theory that COVID-19 leaked from a lab in Wuhan has been gaining momentum, with top US adviser on the COVID-19 pandemic Dr Anthony Fauci coming under fire by critics who say he downplayed the possibility of a lab leak.

The theory always existed, with Australian officials and the World Health Organization (WHO) stressing it was a slim possibility with no solid conclusions on the virus’s origin drawn, calling for further investigations.

Many organisations have had to do an about-face on their coverage, with The Washington Post correcting a previous article that described the lab leak theory as a debunked conspiracy — calling it a “coronavirus fringe theory that scientists have disputed”.

Theories swirl, are shut down

The lab leak theory emerged almost immediately, speculating that either the virus was engineered in the Wuhan Institute of Virology lab, or was collected from the wild and leaked, accidentally or otherwise.

It was shut down by many almost as quickly as it started. On February 19, 2020, medical journal The Lancet published a statement signed by 27 scientists rejecting the lab-leak hypothesis and condemning “conspiracy theories” that COVID-19 didn’t have a natural origin.

While senior officials from the Trump administration, including then-president Donald Trump and then-secretary of state Mike Pompeo, touted the theory, Australian intelligence officials were unable to find any evidence to support it. Liberal National MP George Christensen questioned the theory in Parliament several times.

The WHO said the virus was “natural in origin”, and Health Minister Greg Hunt pointed to the likelihood the virus was zoonotic, meaning it spread from animals to humans: “There is a very real likelihood that this disease arose from a wet market in Wuhan,” he said on April 17, though later stressed the original source of the virus hadn’t been determined.

On April 29, Hunt walked back his comments, saying it was “not the government’s position” that the virus originated in the wet market.

While many were deterred, News Corp was not: on May 2, The Daily Telegraph’s Sharri Markson published her article on a “leaked” Five Eyes report — later revealed to be a reference paper of background research distributed by the US state department — stating intelligence agencies in Australia, Canada, New Zealand, the UK and the US were looking into the work of two Chinese scientists who studied bats in Australia. The report was three months old, though Markson noted the Australian government believed the chance the virus came from a lab was 5%.

At the time, Media Watch discredited the report, pointing to “overwhelming” evidence COVID-19 jumped from animals to humans.

“Markson should have told readers that almost every virus expert had dismissed the lab escape theory,” Media Watch host Paul Barry said.

A few days after Markson’s article, Prime Minister Scott Morrison was asked about the theory.

“There’s nothing that we have that would indicate that was the likely source,” he said. “You can’t rule anything out in these environments … The most likely scenario that has been canvassed relates to wildlife wet markets, but that’s a matter that would have to be thoroughly assessed.”

Markson also quoted a “military document” that apparently showed China discussed weaponising coronaviruses since 2015 — though it was later revealed to be sourced from a book.

Zoonotic evidence emerges

As Australia continued to push for an investigation into the origins of the COVID-19 pandemic — causing tension with China — the lab leak theory continued to swirl, with Markson quoting four experts who questioned the virus’s origin in June.

“This is precisely why, precisely why, we argue for an impartial independent and comprehensive international investigation,” Hunt said when asked about the article.

Following a trip to Wuhan in February, the WHO all but dismissed the lab leakage theory, which Hunt said was pleasing.

Just a month later, however, WHO director-general Dr Tedros Adhanom Ghebreyesus said further studies were needed.

“As far as WHO is concerned, all hypotheses remain on the table. This report is a very important beginning, but it is not the end. We have not yet found the source of the virus, and we must continue to follow the science and leave no stone unturned as we do,” he said.

He later said the lab leak theory “did not receive the same depth of attention and work as the other hypotheses”.

Theory now gaining traction

On May 14 of this year, 18 prominent scientists signed an open letter published in medical journal Science calling for more investigation into the origins of the pandemic following the WHO report.

On May 26, a classified US intelligence report was leaked saying three researchers at the Wuhan laboratory were treated in hospital in November 2019. Fauci has said he’s “not convinced” the virus originated naturally, though says it’s overwhelmingly likely the SARS-COV-2 virus transferred into humans from animals.

US President Joe Biden revealed he’d ordered a review into the COVID-19 lab leak theory upon assuming office. Importantly, he did so after shutting down an investigation launched under Donald Trump’s presidency that Biden’s administration deemed poor quality.

He said the US intelligence community had “coalesced around two likely scenarios” and that a definitive conclusion would be reached by late August.

The coverage led Paul Barry to say that should the lab theory prove correct, the organisation would update its viewers and “apologise to Ms Markson for our criticism”.

The theory has made it back into Parliament, with Liberal MP Kevin Andrews saying the pandemic came “possibly from a biological laboratory”.

Hunt and Morrison have been contacted for comment.