There is no scientifically validated evidence to support the theory that the coronavirus leaked from a laboratory in China, and more recent, peer-reviewed studies strongly suggest that the virus evolved in nature, a group of scientists wrote in The Lancet journal.
The report published on Monday was compiled by two dozen biologists, ecologists, epidemiologists, physicians, public health experts and veterinarians from around the world.
"We believe the strongest clue from new, credible, and peer-reviewed evidence in the scientific literature is that the virus evolved in nature, while suggestions of a laboratory-leak source of the pandemic remain without scientifically validated evidence that directly supports it in peer-reviewed scientific journals," the authors wrote in the journal.
The same team of scientists had last year dismissed the lab leak idea as a conspiracy theory in a report also published in The Lancet.
The latest report comes as many countries have called for further inquiry into the origins of the coronavirus, including the possibility that it escaped from a lab in the Chinese city of Wuhan, where the first cases were reported in December 2019.
"Allegations and conjecture are of no help as they do not facilitate access to information and objective assessment of the pathway from a bat virus to a human pathogen that might help to prevent a future pandemic," the authors of the report explained.
"New viruses can emerge anywhere… It is time to turn down the heat of the rhetoric and turn up the light of scientific inquiry if we are to be better prepared to stem the next pandemic," they noted.
The authors of the report, however, said they welcome calls for scientifically rigorous investigations into the origin of the virus.
"To accomplish this, we encourage WHO and scientific partners across the world to expeditiously move to continue and further extend their initial investigation with experts in China and the Chinese Government," they wrote.
They noted that WHO's report from March, 2021 must be considered the beginning rather than the end of an inquiry.
That inquiry had concluded that a lab leak was unlikely.
However, many countries had expressed concern about the way the investigation was carried out and called for more transparency.
The authors of the Lancet report said they strongly support the call by the Group of Seven (G7) leaders of industrialised nations for "a timely, transparent, expert-led, and science-based WHO-convened phase 2 COVID-19 origins study."
"We also understand that it might take years of field and laboratory study to assemble and link the data essential to reach rational and objective conclusions, but that is what the global scientific community must strive to do," they added.
The authors included scientists from Boston University, University of Maryland in the US, the University of Glasgow, The Wellcome Trust, UK, Charite–Universitatsmedizin Berlin, Germany, and The University of Queensland in Australia among many other global institutes.