The coronavirus has killed 213 people and sickened more than 9,700 in China so far, with dozens more cases confirmed elsewhere, and the World Health Organisation has declared it a global public health emergency.

The paper was widely circulated on Chinese social media, with many people criticising the experts, accusing them of sitting on the information so that they could publish the research to help their careers, and questioning whether there was a cover-up of the outbreak.

It began with Wang Liming, a biology professor at Zhejiang University, who wrote in a post on Weibo, China’s Twitter, that he was “more than outraged, and literally speechless” after reading the paper on Thursday.

“This is the first solid proof that human transmission was intentionally hidden from the public,” he said.

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Wang said the paper had concluded there was clear evidence the virus was being transmitted between humans in early January, when local officials were saying there was none.

The post was later deleted. Much of the criticism that followed has also pointed to similar papers published by Chinese doctors in the past week. People have expressed anger online that there was apparently systematic and detailed statistics of the confirmed cases available, yet official announcements had only provided general information about patients’ travel history, gender, age and symptoms.

There has also been mounting criticism over a perceived delay in the official warnings and disclosure of the outbreak, which authorities had claimed was under control until late January.

The backlash over the paper was further complicated by a directive issued by the Ministry of Science and Technology on Wednesday, urging all scientists to focus on fighting the coronavirus instead of publishing research.

“Use your research results to fight the epidemic, and stop spending time on publishing papers before this is brought under control,” said the directive, posted on the ministry’s website.

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Responding to the criticism, researchers and scientists said they did not have early access to the medical data, while a legal expert said the CDC may not be authorised to disclose information to the public.

Feng Zijian, deputy head of the CDC and one of the authors of the paper, told mainland news outlet Caixin that the data was received on January 22, and the paper was submitted around January 25 or 26.

That would mean the data was obtained after the information on human transmission was disclosed. The city of Wuhan was placed under lockdown on January 23.

Former deputy head of the CDC, Yang Gonghuan, who was not involved in the paper, said there was a huge difference between experts concealing facts and a slow policy reaction.

Law professor Qin Qianhong said it was not clear which government department in China was responsible for disclosing details in the event of a virus outbreak.

“The CDC is more like a think tank or advisory body affiliated with the government,” said Qin, from Wuhan University. “And the laws are not clear about who is responsible or has the power to make information public.”

He said that under the prevention and treatment of infectious diseases law, the National Health Commission had the power to disseminate that information, and provincial governments could only do so when they got the go-ahead from the NHC.

Qin added that local governments were also empowered to issue warnings or notifications about a disease outbreak under other laws and regulations.

Wuhan’s under-fire mayor Zhou Xianwang has blamed a delay on disclosing the latest updates on the outbreak earlier in January on the need to get approval from more senior officials.