However the theory that the virus might have come from a leak in a laboratory "requires further investigation, potential with additional missions involving specialist experts," Dr Tedros said on Tuesday.WUHAN 2019
"Let me say clearly that as far as WHO is concerned, all hypothesis remain on the table," he added.
The virus was first detected in Wuhan, in China's Hubei province in late 2019. An international team of experts travelled to to the city in January to probe the origins of the virus.
Their research relied on samples and evidence provided by Chinese officials but Dr Tedros said the team had difficulty accessing raw data and called for "more timely and comprehensive data sharing" in the future.