The head of the WHO tonight insisted the theory that Covid emerged from a Wuhan lab has not been ruled out - as he said China should help solve the mystery out of 'respect' for the dead.
The body's director general Dr Tedros Adhanom Ghebreyesus suggested that Beijing had not cooperated fully as he urged more 'transparency' in the continuing investigation.
There has been mounting controversy over how the virus first emerged - whether through animal contact at a 'wet' market in Wuhan or leakage from a highly secure research laboratory in the same city as some have suggested.
China says it is not responsible for the pandemic and has dismissed conspiracy theories about the disease being manmade.
However, last month Joe Biden ordered US intelligence agencies to report in the next three months on whether the Covid-19 virus first emerged in China from an animal or from a laboratory accident.
Asked whether the possibility of a lab leak was still on the table, Dr Tedros told a G7 summit briefing that currently 'every hypothesis should be open'.
He said at least 174million people were confirmed as having contracted the disease so far and 3.75million had died.
'I think the respect these people deserve is knowing what the origin of this virus is so that we can prevent it from happening again,' he added.
Dr Tedros suggested there had not been enough 'transparency and cooperation' from China in the initial stages of the investigation.
'We need cooperation from the Chinese side. We need transparency to understand and know or find the origins of this virus,' he added.
'There were difficulties in data sharing, especially raw data… (we) hope the next phase there will be better cooperation and transparency.'
UK ministers have also demanded China cooperate fully with probes into the origins of the disease.
Last month Mr Biden ordered agencies to 'redouble their efforts to collect and analyse information' and report back in 90 days.
According to Mr Biden, the intelligence services are currently split over the two possible sources for the virus that swept the planet over the past year, killing millions of people.
The recent increases in Covid-19 cases and deaths represent “truly worrying trends,” said WHO Director General Tedros Adhanom Ghebreyesus https://t.co/eRcCf6xGy8— Bloomberg (@business) March 24, 2021
Mr Biden said that in March he asked for a report on the origins of the virus, including 'whether it emerged from human contact with an infected animal or from a laboratory accident.'
There have been claimed that three researchers at the Wuhan lab were hospitalised with Covid-19-like symptoms in November, a month before China said it discovered the first cases of the virus.
This article has been adapted from its original source.
© Associated Newspapers Ltd.