A worker inside the P4 laboratory in Wuhan, capital of China's Hubei province.

The Chinese virology institute in Wuhan where COVID-19 first emerged has three live strains of bat coronavirus on-site, but none match the new contagion wreaking chaos across the world

Scientists believe COVID-19 — which first emerged in Wuhan and has claimed some 340,000 lives across the globe — originated in bats and could have been transmitted to people via another mammal.

The director of the Wuhan Institute of Virology told state broadcaster CGTN that claims made by US President Donald Trump and others the virus could have leaked from the facility were “pure fabrication”.

In the interview broadcast on Saturday night, Wang Yanyi said the centre has “isolated and obtained some coronaviruses from bats.”

“Now we have three strains of live viruses… But their highest similarity to SARS-CoV-2 only reaches 79.8 percent,” she said, referring to the coronavirus strain that causes COVID-19.

One of their research teams, led by Professor Shi Zhengli, has been researching bat coronaviruses since 2004 and focused on the “source tracing of SARS”, the strain behind another virus outbreak nearly two decades ago.

“We know that the whole genome of SARS-CoV-2 is only 80 percent similar to that of SARS. It’s an obvious difference,” she said.

The lab has said it received samples of the then-unknown virus on December 30, determined the viral genome sequence on January 2 and submitted information on the pathogen to the WHO on January 11.

Wang said in the interview that before it received samples in December, their team had never “encountered, researched or kept the virus.”

“In fact, like everyone else, we didn’t even know the virus existed,” she said.

“How could it have leaked from our lab when we never had it?”

The World Health Organization said Washington had offered no evidence to support the “speculative” claims.