Yuan said that when the outbreak occurred in Wuhan in December 2019, the institute quickly confirmed the pathogen was a new coronavirus, isolated the strain and analyzed and shared its full genome sequence with the world.

"These research results have laid a foundation for developing tests, screening for antiviral drugs and vaccine research, and have bought time for the global fight against the disease," he said.

Yuan said unfounded accusations that the institute was the source of the outbreak had disrupted its scientific research as well as international communication and cooperation.

From Jan 14 to Feb 10, Chinese and international experts organized by the World Health Organization visited Wuhan to study the origin of the virus.

Liang Wannian, head of Chinese experts on the WHO-convened mission, said that 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.

If some scientists still decide to pursue this hypothesis, Liang said, Chinese researchers have suggested that they direct attention to P4 laboratories in other countries, which have so far not been visited by outside experts, and review these labs for possible safety risks and leak incidents.