LONDON: The possibility the Covid virus leaked from a laboratory should not be ruled out, a former top Chinese government scientist has said, reported German news agency (dpa).

The view of virologist and immunologist Professor George Gao is in stark contrast to that of the Chinese government which dismisses any suggestion the virus may have originated in a Wuhan laboratory.

Gao, the former head of China's Centre for Disease Control (CDC), told the BBC Radio 4 podcast "Fever: The Hunt for Covid's Origin": "You can always suspect anything. That's science. Don't rule out anything."

Gao is now vice president of the National Natural Science Foundation of China after retiring last year from the CDC, where he played a key role in the pandemic response and efforts to trace how it started.

The Chinese embassy in the UK told the BBC: "The so-called 'lab leak' is a lie created by anti-China forces. It is politically motivated and has no scientific basis."

The theory that the virus accidentally leaked from a laboratory resurfaced in February when FBI director said this is where it "most likely" originated - although there is no consensus among US intelligence agencies on the question.

The BBC reports that many scientists say the weight of evidence suggests that a natural origin - the virus spreading from animals to humans - is the most likely scenario.

The idea the virus infected someone involved in research that was designed to better understand the threat of viruses emerging from nature is another suggestion.

Wuhan is home to the Wuhan Institute of Virology (WIV), one of China's top national laboratories known to have spent years studying coronaviruses.

Professor Gao told the BBC some kind of formal investigation into the WIV was carried out and "that lab was double-checked by the experts in the field".

Stating he has not seen the result but has "heard" that the lab was given a clean bill of health, Gao added: "I think their conclusion is that they are following all the protocols. They haven't found (any) wrongdoings."

Wuhan's Huanan Seafood Market and hospitals near it were the focus of searches for potential explanations for the virus early in the pandemic.

An investigation into Covid's origin by the World Health Organisation said it was "extremely unlikely" the virus leaked from a lab.

Plans for a second phase of the investigation, involving audits of laboratories in the Wuhan area, were rejected by the Chinese government, the podcast adds.

-- BERNAMA