Experts from the World Health Organization (WHO), who investigated the origins of Covid-19 in Wuhan, must also extend their probe to labs in other countries as the virus may have jumped to humans outside China, said a Chinese scientist leading the country’s WHO team.

Wuhan might not be the place from where SARS-CoV-2 — the virus that causes Covid-19 — jumped to humans, Liang Wannian, China’s key expert in the joint inquiry with the UN health body, was quoted as saying to the South China Morning Post.

The WHO must probe countries where the virus had been found in animals, the environment, and human samples earlier than the Wuhan outbreak in 2019, said Wannian, who is also a Professor with the Vanke School of Public Health at Tsinghua University in Beijing.

Further, countries that exported cold-chain products to the Wuhan’s Huanan Seafood Market, widely considered as the source of the outbreak of Covid-19, should also be probed, he added.

“We recommend that WHO conduct a review and analysis of earlier suspected cases, earlier evidence found in animal and environmental studies that were published, to determine the scientific validity and reliability of the available evidence,” Wannian said.

“The focus of phase 2 should be based on publicly available research evidence. As the pathway of virus transmission from natural hosts via intermediate hosts is the most likely, studies should be conducted in all countries where horseshoe bats and pangolins are distributed, particularly in areas where sampling is under-tested,” he added.

Wannian said the “effective working mechanisms and methods” used during the WHO mission to China could be used in other countries, and it should be done in a way that ensured “maximum scientific accuracy, validity, legitimacy, and fairness”, the report said.

Moreover, the second group of investigators should be the same as it will ensure professionalism and continuity”, Wannian said. “I think the WHO should be fully aware of this from a scientific point of view.”

Wannian also stated that the host country should have a say in the experts taking part to fully respect’ their national sovereignty.

“In order to fully respect the national sovereignty of the next country conducting the new coronavirus tracing study, the final composition of the expert group should be mutually agreed between the host country and the WHO, with the leader of the expert group being a technical expert or official of the WHO Secretariat and an expert recommended by the host country,” he was quoted as saying to the Post.

A team of experts from the WHO had in January, spent four weeks in China to investigate whether the Covid-19 pandemic emerged from a genetically modified virus that leaked from the infamous Wuhan Institute of Virology (WIV). Their report, in March, concluded that a laboratory leak was “extremely unlikely”.

However, undermining the report, the WHO director-general Tedros Adhanom Ghebreyesus, last month, stated that it was premature on the global health body’s part to rule out a potential link between the Covid pandemic and a laboratory leak.

Asking China to be more transparent on the issue of data sharing, he proposed a second phase of studies which included audits of laboratories and markets in Wuhan. China rejected the probe, accusing the WHO of “arrogance” and a “disrespect for common sense”.