A joint investigation by the W.H.O. and China found that said it was “extremely unlikely” that the coronavirus escaped from a Wuhan lab, according to a report released in March. Many scientists say that the virus most likely jumped from animals to people through natural spillover in a market or a similar setting.
But some scientists have said that the initial inquiry was premature in dismissing the lab leak idea. The United States and other governments have pressed China to share more information, especially from the Wuhan Institute of Virology.
At the news conference on Thursday, several Chinese officials asserted that the W.H.O. inquiry got it right the first time, and that there was no evidence to justify renewed checks of the labs. The W.H.O. investigators should instead focus their search on signs of natural transmission, they said, and the possibility that the virus may have first spread outside China.
In recent days, a spokesman for the Chinese foreign ministry and Global Times, a news outlet overseen by the Chinese Communist Party, have gone even further in pushing back against the demands on Beijing. They have reiterated claims — widely dismissed by scientists — that the coronavirus may have escaped from a U.S. military laboratory. A petition organized by Global Times calling for an inquiry into the American facility claims to have collected nearly six million signatures.