A first report by the team of scientists assembled by the World Health Organization concludes that SARS-CoV-2 originated in animals but left open the possibility the virus, more commonly known as COVID-19, escaped from a lab in China.
The team said in the report released Friday that it had not been provided with any data to evaluate the "laboratory leak" theory and that "further investigations" are needed.
The virus was first detected in late 2019 in Wuhan, China, with the explanation in had jumped from animals to humans at an exotic food market in that city, which also is home to the Wuhan Institute of Virology.
WHO-backed scientists visited the lab in early 2021 but reportedly left disappointed about not being given access to vital data.
Bats, according to the report, likely carried an ancestor of the virus that may have made its way into a mammal sold at a wildlife market, but researchers said incomplete data means they were not able to identify which animal infected humans.
The report reads, "it remains important to consider all reasonable scientific data" that could support a lab leak theory.
"All hypotheses must remain on the table until we have evidence that enables us to rule certain hypotheses in or out," WHO Director-General Tedros Adhanom Ghebreyesus said following the report's release.
He also urged all countries, especially China, to be transparent with available data.
The group that authored the report – the Scientific Advisory Group for the Origins of Novel Pathogens (SAGO) – did not conduct its own investigation, rather, relied on on reviewing available research. Some members of the group from China, Russia, and Brazil rejected the idea of evaluating a lab leak theory because "from their viewpoint, there is no new scientific evidence," the report also states.
China has consistently been accused of withholding information from the SAGO team. The White House says it does not believe China has been transparent in releasing its COVID origins findings and has attempted to severely limit every semi-independent investigation into the question.