A patient died on Saturday from a mysterious illness after an outbreak in the central Chinese city of Wuhan, according to the local health commission.
The emergence of the virus is raising concerns as hundreds of millions of people are getting ready to travel during the Chinese New Year holiday later this month.
Experts who analysed the gene sequencing of the virus think it could be triggered by a new type of coronavirus, according to Chinese state broadcaster CCTV.
A total of 41 people have been diagnosed with the coronavirus.
Seven people are still in critical condition, and two have been released from hospital, with no new infections detected for the last week, Wuhans health commission said.
Most of those with the illness are workers at or visitors to a particular market in Wuhan which sells fish and wild animals, the World Health Organisation said.
It is not clear if the disease is being passed from person to person, the commission said, adding that of the more than 700 people who have come into contact with the patients, none has been infected.
Coronaviruses can infect animals and people, causing diseases ranging from the common cold to severe illnesses such as Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS).
The disease raised an alarm in places like Taiwan, Hong Kong, South Korea, Thailand, and the Philippines, where officials said they would set up quarantine zones or scan passengers from China for signs of the disease.
Symptoms included fever, difficulty breathing, and lung lesions. (dpa/NAN)