The problem for the lab-leak position is that the U.S. has never had access to the Wuhan lab and has thus been unable to reach a definitive answer for more than five years. Now that the CIA has at last come to a conclusion, not all scientists are sold on what it has reported, seeing the results as thinly scientifically sourced.

The CIA says both a natural origin and a lab leak "remain plausible" as potential sources of covid-19, following a review of the pandemic's origins.

It was unclear the extent to which the agency has collected new intelligence on COVID-19's origins and whether that new evidence was used to formulate the latest assessment.

The Central Intelligence Agency previously said that two explanations were plausible, a lab leak or a natural source for the virus. Yet under new agency director John Ratcliffe, the CIA has changed its view, which is now in line with that of the Department of Energy and the Federal Bureau of Investigation.

Langley joins the FBI and Energy Department in agreeing that a lab leak is the most likely source of the pandemic.

The Central Intelligence Agency said the Covid-19 pandemic “more likely” originated from a lab leak than a natural source, shifting its stance after previously saying both scenarios were possible.

Several US agencies and some scientists have proposed the lab leak theory over the past few years. But other experts insist there are good reasons to think the devastating pathogen emerged from a market where animals are traded.