British Intelligence agents said they believe it is "feasible" that Covid-19 was started by a lab leak from a Chinese facility in Wuhan, after President Biden directed the US intelligence community to redouble its efforts in investigating the origins of the Covid-19 pandemic and report back to him in 90 days.

Western intelligence agencies previously felt the virus emerging from the facility was highly unlikely (Picture: Reuters/Getty)

It comes amid growing scrutiny of the origins of the virus, with US President Joe Biden ordering his intelligence agencies to investigate the theory that it emerged from a laboratory.

Beijing has angrily insisted that it was not the source of the outbreak – but has faced international criticism over its previous sharing of information and openness to previous World Health Organisation investigations. Officials are said to expect the Chinese authorities to ‘lie either way’.

It had been understood that Western intelligence services thought there was only a remote chance of the Wuhan Institute of Virology being the source of the virus – but that stance now appears to be evolving.

The laboratory conducts research into bat-derived coronaviruses – including one closely associated with Covid-19 – and now a lab escape is thought to be a possibility, intelligence sources told The Sunday Times.

One said to be familiar with UK involvement in the investigation explained: ‘There might be pockets of evidence that take us one way, and evidence that takes us another way. The Chinese will lie either way.

‘I don’t think we will ever know.’

The changing position is likely to increase tensions with the Chinese authorities, who have been defensive about their handling of the early stages of the pandemic.

Photos: Reuters

Renewed focus on the virology institute – which had been the source of much early speculation ridiculed by some scientists – follows news that three researchers at the institute fell ill in November 2019.

They had to be treated in hospital, reports say.

China first confirmed human-to-human transmission in January 2020, but the disease had then been spreading for weeks.

Many observers originally suspected a wet market in Wuhan to have been the source of the virus, which is believed to have jumped from animals – possibly bats or pangolins – to people.

Why the Wuhan lab-leak origin theory is being taken more seriously

The United States is closer than ever to beating Covid-19, with half the country vaccinated and more restrictions lifting. But we're as far as ever from knowing how this virus, which shut down the world, came to be -- which is as frightening as anything, since there's growing suggestions that it didn't just occur naturally, as many experts have long argued.

The US, with increasing urgency, is calling for more study, warning about the stakes for future pandemics, and more openly considering the idea that mistakes or an accident in a Chinese lab caused the Covid-19 pandemic. President Joe Biden said Wednesday he has directed the US intelligence community to redouble its efforts in investigating the origins of the Covid-19 pandemic and report back to him in 90 days.

The Chinese government says case closed.

(Photo: Getty Images)

A classified US intelligence report - saying three researchers at theWuhan laboratory were treated in hospital in November 2019, just before the virus began infecting humans in the city - began circulating in US media this week.

But it was reported the Biden administration had shut down a US state department investigation, set up by President Trump, into the lab-leak theory.

"That possibility certainly exists, and I am totally in favour of a full investigation of whether that could have happened," Anthony Fauci, President Biden's chief medical adviser, told the US senate committee on 11 May.

A group of prominent scientists with relevant experience criticized theWHO report for not taking the lab leak theory seriously enough -- it was dismissed in a few pages of a several hundred page report.

"We must take hypotheses about both natural and laboratory spillovers seriously until we have sufficient data," the scientists wrote in Science Magazine.

Yet closed doors have also helped conspiracy theories grow. The more evidence there is for the lab leak theory, the more it gives oxygen to the idea that the virus was created intentionally as a bioweapon. There's no evidence specifically supporting that claim and experts still say it is unlikely, according to CNN.

Dr. Paul Offit, an infectious disease expert at the University of Pennsylvania Perelman School of Medicine, told CNN's Wolf Blitzer it was unlikely the Wuhan lab had manipulated the virus to make it more contagious using controversial gain of function research -- but we've got to find out.

Chau Polly