WHO insists 'all available evidence' suggests coronavirus came from an animal and was not created in a lab

The World Health Organisation has insisted that all available evidence suggests coronavirus was not manufactured in a lab. 

Takeshi Kasai, WHO Regional Director for the Western Pacific, said that while it has not been possible to identify the exact source, the disease likely came from animals.

The WHO has previously said that the genetic makeup of the virus is closely related to coronaviruses identified in bats - suggesting the disease originated in that animal before making the leap into humans. 

Mr Kasai spoke out after President Trump said the US is looking into whether the virus leaked from a lab near Wuhan which was doing research on coronaviruses including the SARS virus, a close genetic relative of the current coronavirus.

The WHO has insisted that coronavirus likely originated in animals and was not man-made, amid persistent conspiracy theories that it leaked from a lab in Wuhan (pictured) 

The WHO has previously said the new coronavirus is similar to viruses already identified in a common species of bat (pictured), making them a likely source

German Chancellor Angela Merkel has also called for 'more transparency' from China over the origin of the virus.

Meanwhile Veronika Skvortsova, Russia's former health minister, refused to rule out the possibility that the virus came from a lab and called for a 'very through study'.

WHO West Asia director Takeshi Kasai spoke out as world leaders called for an investigation into the virus's origins

It is thought that the new coronavirus first made the jump from animals to humans at the Huanan Seafood Market in Wuhan, which is where the earliest cluster of cases was detected.

However, China has so far failed to identify 'patient zero' - the first person to catch the infection.

Without knowing who patient zero is or how they were infected, it will be impossible to know the true source of the virus.

The WHO itself admits that the virus could have been carried to the Huanan Market by an already-infected human, who then spread it to others.

Investigations are currently ongoing into possible cases of coronavirus dating back to mid-November 2019, a month earlier than previously thought.

It came as rare footage emerged showing carrying out research at the Wuhan Institute of Virology - which has found itself at the centre of conspiracy theories around the virus's origin. 

A video released by Chinese state broadcaster CCTV in February provides a glimpse into the institute.

The £34million lab is affiliated to the Chinese Academy of Sciences. It was completed in 2015 and officially opened in 2018.

In the clip, one researcher, named Zhang Huajun, demonstrates how he and one colleague put on two layers of protective suits and pass five air-tight chambers before entering the core part of the lab.

The lab is said to have three testing rooms, two animal storage rooms, one virus bank and one animal-dissection room. Twenty-four scientists can work there at the same time.

Researcher Zhang said the building was designed in such a way that air can only flow into the lab from the outside, not the other way around, to prevent leaks.  

Dr Yuan Zhiming, the deputy head of the Wuhan Institute of Virology, hit back at accusations that the virus leaked from his lab in an interview with state media over the weekend.

'There's no way this virus came from us,' Dr Yuan told CGTN, the English-language arm of CCTV. 'I know it's impossible.'

Dr Yuan said that a man-made coronavirus would be beyond human intelligence as he rejected claims that the virus was artificially engineered.

'Some scientists believe that to synthesise a virus requires extraordinary intelligence or workload, so I have never believed that we humans have the capabilities at this time to create such a virus,' he explained.

Dr Yuan attributed the theories to the fact that the institute and the P4 lab are in Wuhan, so 'people can't help but make associations which I think is understandable'.

But he criticised people who 'are deliberately trying to mislead people'. He blamed US senator Tom Cotton and the Washington Post for promoting such claims.

'They have no evidence or knowledge. This is entirely based on speculation,' he denounced.

'Part of the purpose is to confuse people, to interfere with our entire epidemic activities or our scientific activities.'

Although scientists believe that the virus jumped to humans from wild animals sold as food in a market about 10 miles from the lab, conspiracy theorists promote different assumptions.

Some people claim that the virus, formally known as SARS-CoV-2, could be a biological warfare weapon engineered there. Others suspect that it escaped from the lab.

Shi Zhengli, a deputy director at the institute, told the press in February that she 'guaranteed with her own life' that the outbreak was not related to the lab.

The institute also refuted reports which named Huang Yanling, a researcher at the Institute of Virology, as 'patient zero' – the first person to be infected.

'I can tell you for sure that none of our students, retirees or any of our staff has been infected,' Dr Yuan said.

American intelligence services have reportedly launched a full-scale investigation into the lab over claims that scientists there allowed the novel coronavirus to escape as part of a botched experiment, leading to a global pandemic.

China has denied speculation that the pathogen originated inside the Wuhan Institute of Virology lab, though US government agencies are now said to be piecing together a timeline of what authorities in Beijing knew to 'create an accurate picture of what happened'.

Sources told Fox News on Friday that American analysts will present their findings 'in the near term' to President Trump, who will then huddle with aides to determine how to hold China accountable for the pandemic.

The American intelligence sources told Fox News that analysts in Washington have ruled out the theory that the coronavirus was engineered by Chinese scientists as a bioweapon.

Experts note that the genome mapping of the virus indicates that there were no genetic alterations made to it.

US sources told Fox News they believe that 'patient zero' became infected with coronavirus as it was being studied inside the lab.

The infected person then is believed to have spread the virus throughout the city and onwards.

While the exact origin of the virus remains unknown, the broad scientific consensus holds that SARS-CoV-2 came from bats.

COVID-19, the disease caused by the new coronavirus, has killed more than 165,000 people and infected over 2.4 million worldwide since the pandemic began in Wuhan last December.