A WHO expert leading the probe said that the judgment was based on "long, frank, open discussions with researchers and management" at institutions.
A team of World Health Organization (WHO) which is investigating the origins of coronavirus in Wuhan has dismissed the theory of 'lab leak'.
Peter Ben Embarek, the Danish WHO food safety expert leading the international team, said his group will not recommend further investigation into the theory that the virus accidentally leaked from labs conducting coronavirus research, the Washington Post reported.
Embarek told reporters that the judgment was based on "long, frank, open discussions with researchers and management" at institutions including the Wuhan Institute of Virology (WIV).
"They're the best ones to dismiss the claims and provide answers to all the questions," he said.
"Our initial findings suggest that introduction through an intermediary host species is the most likely passway and one that will require more studies and more specific targeted research ... The findings suggest that a laboratory incident hypothesis is extremely unlikely to explain the introduction of the virus into the human population," the WHO expert added.
Peter Daszak, a British member of the WHO mission in Wuhan who has collaborated with the WIV through his EcoHealth Alliance nonprofit, said on Twitter that the decision to downplay the lab theory was a unanimous judgment among the WHO team's 17 members, reported Washington Post.
The global health body on Tuesday said that there is no evidence of coronavirus circulation in any animal species in China.
Embarek stated that four hypotheses on how the virus spread but reiterated that the "laboratory incident hypothesis is extremely unlikely to explain the introduction of the virus into the human population".
"It has not been possible to pinpoint any animal species as a potential reservoir for this disease, and they indicate that currently and also back in 2019 it does not look like there was the circulation of the virus in any animal species in the country," he said.
The four key hypotheses are: direct zoonotic spillover; introduction through intermediary host species; food chain, frozen food products, surface transmission; and finally a laboratory-related incident, Sputnik quoted him as saying.
The investigation by the WHO was undertaken after a cluster of patients exhibiting pneumonia-like symptoms emerged in Wuhan in December 2019, a new coronavirus was identified to be causing the disease, which later became known as COVID-19, and triggered the global pandemic that infected over 90 million people and killed more than 1.9 million, reported Sputnik.
After the outbreak, then US President Donald Trump blamed China for the global COVID-19 pandemic by calling the new coronavirus "Chinese Virus".