A World Health Organization team has dropped its investigation into whether the novel coronavirus escaped from a lab in Wuhan, China, calling the theory "extremely unlikely."
Experts now suggest that COVID-19 was first introduced to humans through animals.
"Our initial findings suggest that the introduction through an intermediary host species is the most likely pathway and one that will require more studies and more specific, targeted research," said Ben Embarek, the WHO food safety and animal diseases expert.
The first cases of the novel coronavirus were discovered in Wuhan in December 2019.
"However, the findings suggest that the laboratory incidents hypothesis is extremely unlikely to explain the introduction of the virus to the human population," Embarek said. "Therefore it is not a hypothesis that we advise to suggest future studies ... into the understanding of the origin of the virus."
Original theories said that the virus had spread from a wet market in the area. The Wuhan Institute of Virology, which collects extensive virus samples, was also suspected of accidentally leaking the virus into the community. China has strongly rejected the claim.