It is a question that has been hotly debated for 14 months, and one likely to be examined for months and years to come.

On Tuesday, World Health Organization food safety and animal diseases expert Peter Ben Embarek said it’s unlikely the virus leaked from a Chinese lab.

Embarek is at the end of a visit to the central Chinese city, where a team of scientists is investigating the possible origins of the virus that causes COVID-19.

„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,” Embarek said. „However, the findings suggest that the laboratory incidents hypothesis is extremely unlikely to explain the introduction of the virus to the human population.”

The first cases were discovered in Wuhan in December 2019. The Wuhan Institute of Virology has collected extensive virus samples, leading to allegations that it may have caused the original outbreak by leaking the virus into the surrounding community. China has strongly rejected that possibility and has promoted other theories that the virus may have originated elsewhere.

The WHO team, consisting of experts from 10 countries, is considering several theories for how the disease jumped from animals to humans.

A popular theory is that it originated in bats before being passed to humans through another species of wild animal, such as a pangolin or bamboo rat, which is considered an exotic delicacy by some in China. Transmission through the trade in frozen products was also a likely possibility, Embarek said.