A Qatari man struck down with a previously unknown virus related to the deadly Sars virus and the common cold is critically ill in hospital in Britain, the World Health Organisation said yesterday.

The UN health body said it is urgently seeking more information about the new virus, which comes from the same family as the Sars virus that emerged in 2002 and killed 800 people.

Peter Openshaw, director of the Centre for Respiratory Infection at Imperial College London, said the virus was unlikely to prove a concern, but experts would watch out for any sign of it spreading.

The 49-year-old patient has symptoms of an acute respiratory infection and kidney failure, the WHO said, without giving details of which hospital he was staying in.

“We are still investigating this. We’re asking for information from whoever might have seen such cases, but as of the moment we haven’t had any more notifications of cases,” Gregory Hartl, spokesman for the Geneva-based WHO, said.

The WHO issued a statement late on Sunday through its “global alert and response” system saying tests on the Qatari man had confirmed the presence of a new coronavirus.

“Given that this is a novel coronavirus, WHO is currently in the process of obtaining further information to determine the public health implications,” the statement said.

Coronaviruses are a large family of viruses which includes the common cold and Sars.

Sars, or Severe Acute Respiratory Syndrome, appeared in China in 2002 and infected more than 8,000 people around the world, killing around 800 of them before being brought under control.

The WHO said the Qatari patient had gone to the doctor on September 3, suffering from the symptoms of an acute respiratory infection.

On September 7, he was admitted to an intensive care unit in Doha, Qatar, and on September 11, the man, who had also recently been in Saudi Arabia, was transferred to Britain by air ambulance from Qatar.