The Wuhan laboratory at the centre of the controversy "never had the virus," said Liang Wannian, an epidemiologist who headed the team of Chinese experts working with the WHO. While China has consistently rejected the lab hypothesis, officials sought to draw a line today

China pushed back against the World Health Organization's call for another probe into the coronavirus's origins that includes examining whether it leaked from a lab, saying there's no evidence for the theory and it defies common sense.

The pathogen most likely arose in an animal, which transmitted it to humans via an intermediate host, a group of top Chinese science officials insisted at a briefing in Beijing on Thursday. They praised an earlier report from the WHO that pointed primarily to animals, while finding that the lab leak hypothesis was "extremely impossible."

The Wuhan laboratory at the centre of the controversy "never had the virus," said Liang Wannian, an epidemiologist who headed the team of Chinese experts working with the WHO. "There's no need for us to put more resources into a lab leak probe."

The hypothesis was once dismissed as a conspiracy theory by opponents of former U.S. President Donald Trump, whose administration raised the possibility ahead of the 2020 election. The premise subsequently gained traction as scientists questioned China's reluctance to provide access to primary source material, attention grew over efforts among some virologists to make viruses stronger, called "gain of function" work, and some world leaders called for a deeper probe.

While China has consistently rejected the lab hypothesis, officials sought to draw a line in the sand Thursday, signalling Beijing won't engage on the origin hunt if the theory remained in play. It was China's most direct pushback to date on calls from the WHO and others to investigate the Wuhan Institute of Virology's high-level lab, which studied bat-borne pathogens and other coronaviruses.

"The plan on the second phase of the origin study, it contains language that does not respect science or common sense," said Zeng Yixin, vice minister of the National Health Commission. "We won't follow such a plan."

U.S. President Joe Biden in May said the U.S. intelligence community was divided on whether the virus emerged from human contact with animals or from a laboratory accident, and he ordered them to "redouble their efforts" and report back by late August. The move renewed suspicion that the virus could have escaped from the Wuhan Institute of Virology, where researchers are known to have been studying other coronaviruses.

Chinese officials said they are committed to uncovering the origins of the novel coronavirus, a matter that deserves serious study and should be based on science. The WHO's plans to make the lab leak hypothesis a priority for the next stage of research has been contaminated by political posturing and displays "arrogance against science," Zeng said.