A 61-year-old man has died from mystery a virus which has infected Chinese and Hong Kong citizens as authorities race to contain the outbreak.

The pneumonia-like illness has been traced to the central Chinese city of Wuhan where the man died and seven others remain in a critical condition, the Wuhan health authorities say.

In total, 41 people have been diagnosed with the pathogen which had sparked initial fears of a SARS revival.

Preliminary lab tests cited by Chinese state media earlier this week pointed to a new type of coronavirus, the Wuhan Municipal Health Commission said in a statement on its website.

Two of them have been discharged from hospital and the rest are in a stable condition, while 739 people deemed to have been in close contact with the patients have been cleared, it said.

The man – the first victim of the outbreak that began in December – was a regular buyer at the seafood market which was considered ground zero of the disease.

He had been previously diagnosed with abdominal tumours and chronic liver disease, the health authority said.

Treatments did not improve his symptoms after he was admitted to hospital and he died on the evening of Jan. 9 when his heart failed.

The commission added that no new cases had been detected since January 3.

The Wuhan health authority also said patients were mainly vendors and purchasers at the seafood market in the city, and that to date no medical staff had been infected, nor had clear evidence of human-to-human transmission been found.

The World Health Organisation said that a newly emerging member of the family of viruses that caused the deadly Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS) outbreaks, could be the cause of the present outbreak.

Coronaviruses are a large family of viruses that can cause infections ranging from the common cold to SARS. Some of the virus types cause less serious disease, while some like the one that causes MERS, are far more severe.