One of the UK's top virologists today said she couldn't rule out the possibility that the coronavirus had leaked out of a science lab in Wuhan.
Professor Wendy Barclay, a member of the SAGE advisory group and infectious disease expert at Imperial College London, said she thought the accepted idea that the bug spread to humans in an animal market was 'much more likely'.
Quizzed by MPs on the science committee this morning, Professor Barclay said viruses transmit from creatures to people in live markets 'very, very frequently'.
Her comments came amid growing doubts about the original theory that the virus emerged naturally, with critics lashing back against scientists who refused to entertain the idea it was being studied in a Chinese lab and escaped by accident.
US infectious diseases boss Dr Anthony Fauci has faced calls to resign over the scandal after he last year dismissed the theory as nonsense but appeared to be considering it behind closed doors.
And scientists who put their names to a letter denouncing the 'lab leak' theory last year have since changed their minds and said a full inquiry is required.
President Joe Biden has ordered a full investigation into the origin of the pandemic virus and demanded scientists work out whether there is truth to the theory.
Professor Wendy Barclay, a member of SAGE and infectious disease expert at Imperial College London, told MPs today that she 'could not exclude the possibility' of a lab leak but that a natural jump was more likely
The accepted wisdom has been that the virus emerged in a bat and then spread to people in the Huanan Seafood Market in Wuhan (pictured) in late 2019, but there is a growing counter-argument that the virus existed before this and could have been leaked from the Wuhan Institute of Virology nearby
Professor Barclay said today: 'I’ll say with high confidence it came from an animal source. That's my answer – high confidence it came from an animal.'
But the MP questioning her, Aaron Bell – a Conservative who represents Newcastle-under-Lyme in Staffordshire and sits on the science committee – probed further.
He asked: 'Originally from an animal source, but is it possible that it was then being studied in a lab and it could have then leaked from the lab?'
Professor Barclay replied: 'I cannot exclude that possibility.
'But I would point out that we have instances of six other coronaviruses emerging into the human population where we don’t think that is the case.
'On the probability, I would say it’s much more likely, knowing where viruses are and live markets with animals mixed. For example, with the virus I’m more familiar with, influenza, that’s where you see zoonotic events happening very, very frequently.
'I would suggest that the opportunity for the virus to jump from an animal source into humans in the part of the world where we first saw this virus emerge is very, very high.'