China has exonerated a doctor who was officially reprimanded for warning about the coronavirus outbreak and later died of the disease, a startling admission of error by the ruling Communist Party that generally bodes no challenges to its authority.

The party's top disciplinary body said the police force in Wuhan had revoked its admonishment of Dr Li Wenliang that had included a threat of arrest.

It also said a "solemn apology" had been issued to Dr Li's family and that two police officers, identified only by their surnames, had been issued "disciplinary punishments" for the original handling of the matter.

In death, Dr Li became the face of simmering anger at the ruling Communist Party's controls over information and complaints that officials lie about or hide disease outbreaks, industrial accidents, natural disasters and financial frauds, while punishing whistleblowers and independent journalists.

AP

After seeing thousands of new cases daily at the peak of the city's outbreak a month ago, Wuhan on Friday had its second consecutive day with no new confirmed or suspected cases.

Police in December had reprimanded eight doctors including Dr Li for warning friends on social media about the emerging threat.

China's supreme court later criticised the police, but the ruling party continued to tighten its grip on information about the outbreak.

In Wuhan, local leaders were accused of telling doctors in December not to publicise the spreading virus in order to avoid casting a shadow over the annual meeting of a local legislative body.

As the virus spread, doctors were ordered to delete posts on social media that appealed for donations of medical supplies. That prompted complaints authorities were more worried about image than public safety.

Dr Li was detained by police after warning about the virus on a social media group for his former classmates.