Peter Ben and Barrack, who led the team in its nearly month long visit, said the virus could have taken a very long and convoluted path, also involving movements across borders.

All the work that has been done on the virus and trying toe identify its origin continue to point towards natural reservoir off thes virus and similar viruses in bad population.

But, he added, it's unlikely that the bats were in Wuhan.

He said they were also looking for Chinese blood samples that could indicate that the virus was circulating earlier than first thought.

The team of investigators did rule out the possibility that the virus leaked from a lab, which has been the subject off conspiracy theories.

The findings suggest that the laboratory incident, uh hypothesis is extremely unlikely and to explain the introduction of the virus into the human population.

The team is also identified market vendors selling frozen animal products, including farmed wild animals.

They plan to further investigate cold chain transmission.

China has pushed the idea that the virus can be transmitted from frozen food and has repeatedly announced findings off coronavirus traces on imported food packaging.

Members of the team have sought to rein in expectations for the mission, with one experts saying it would probably take years to fully understand the origins of covert 19.