The Covid pandemic is most likely to have been caused by a Chinese lab leak, according to a US intelligence report.
The classified findings sent to the White House and members of Congress reveal that the US energy department agrees with the FBI that the origin of the virus came from a lab, the Wall Street Journal reported.
The Chinese city of Wuhan was at the epicentre of the outbreak and there are theories the virus leaked there, although other experts believe it was a natural event.
The study from the energy department is significant, although it said it had made its judgment with “low confidence”, adding it did not believe that Covid-19 was part of a Chinese biological weapons programme. The FBI said its findings were made with “moderate confidence”.
National security adviser Jake Sullivan declined to confirm the study on Sunday, saying only that President Joe Biden had asked for as much intelligence as possible about the origins of the pandemic.
Mr Sullivan said: “President Biden specifically requested that the national labs, which are part of the energy department, be brought into this assessment because he wants to put every tool at use to be able to figure out what happened here.”
There are a “variety of views in the intelligence community”, he added.
Senator Dan Sullivan said Congress needed to hold extensive hearings to decide the origin of the virus.
Referring to China, he said: “This is a country that has no problem coming out and lying to the world.”
David Relman, a Stanford University microbiologist, welcomed the latest findings.
He said: “Kudos to those who are willing to set aside their preconceptions and objectively re-examine what we know and don’t know about Covid origins.
“My plea is that we not accept an incomplete answer or give up because of political expediency.”
The energy department’s findings are a swift departure from previous studies and theories on how Covid-19 emerged. The Journal reports that four other agencies and the National Intelligence Council believe the virus was caused by natural transmission.
Two other government bodies, one of which is identified as the CIA, remain undecided.
China denies the virus came from one of its labs.