Liang Wannian, head of Chinese experts on the WHO-convened mission, said to fully assess the "laboratory leak" theory, the team had conducted field inspections at the institute, and in particular, learned about the institute's implementation of management and safety regulations, as well as its past and current research projects.

"The joint expert panel had already performed detailed reviews and inspections of the lab in Wuhan, and reached the conclusion that it is extremely unlikely that the virus originated from a laboratory," he said.