China cannot accept the World Health Organisation's plan for the second phase of a study into the origins of Covid-19, a senior Chinese health official said.
Zeng Yixin, the vice minister of the National Health Commission, said he was "rather taken aback" that the plan includes further investigation of the theory that the virus might have leaked from a Chinese lab.
He dismissed the lab leak idea as a rumour that runs counter to common sense and science.
"It is impossible for us to accept such an origin-tracing plan," he said at a news conference called to address the Covid-19 origins issue.
The search for where the virus came from has become a diplomatic issue that has fuelled China's deteriorating relations with the US and many US allies.
The US and others say that China has not been transparent about what happened in the early days of the pandemic.
China accuses critics of seeking to blame it for the pandemic and politicising an issue that should be left to scientists.
Tedros Adhanom Ghebreyesus, the director-general of WHO, acknowledged last week that there had been a "premature push" after the first phase of the study to rule out the theory that the virus might have escaped from a Chinese government lab in Wuhan, the city where the disease was first detected in late 2019.
Most experts do not think a lab leak is the likely cause.
The question is whether the possibility is so remote that it should be dropped, or whether it merits further study.
The first phase was conducted earlier this year by an international team of scientists who came to Wuhan to work with their Chinese counterparts.
The team was accused of bowing to demands from the Chinese side after it initially indicated that further study was not necessary.
Mr Zeng said the Wuhan lab has no virus that can directly infect humans and noted that the WHO team concluded that a lab leak was highly unlikely.
He added that speculation that staff and graduate students at the lab had been infected and might have started the spread of the virus in the city was untrue.
Yuan Zhiming, the director of the biosafety lab at the Wuhan Institute of Virology, said they had not stored or studied the new coronavirus before the outbreak.
"I want to emphasise that .... the Wuhan Institute of Virology has never designed, made or leaked the novel coronavirus," he said.
The WHO team concluded that the virus most likely jumped from animals to humans, probably from bats to an intermediate animal.
The experts visited markets in Wuhan that had sold live animals, and recommended further study of the farms that supplied the market.
"In the next step, I think animal tracing should still be the priority direction.
"It is the most valuable field for our efforts," Liang Wannian, who headed the Chinese side, said at Thursday's news conference.
Dr Tedros said last week that he hoped for better cooperation and access to data from China.
"We are asking China to be transparent, open and cooperate, especially on the information, raw data that we asked for in the early days of the pandemic," he said.
His words were echoed at the same virtual news conference by Germany's health minister, Jens Spahn, who called on China to intensify cooperation in the search for the origin of the virus.
Mr Zeng said China has always supported "scientific virus tracing" and wants to see the study extended to other countries and regions.
"However, we are opposed to politicising the tracing work," he said.
China has frequently sought to deflect accusations that the pandemic originated in Wuhan and was allowed to spread by early bureaucratic missteps and an attempted cover-up.
Government spokespersons have called for an investigation into whether the virus might have been produced in a US military laboratory, a theory not widely shared in the scientific community.
China has largely ended local transmission of Covid through lockdowns and mask-wearing requirements, and has now administered more than 1.4 billion doses of Chinese vaccines.
Just 12 new domestically spread cases were reported Thursday and China's death toll from the virus has remained unchanged for months at 4,636.
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules here