A third member of a family in the UK has been infected with a new respiratory illness similar to the deadly Sars virus, officials say.
It strengthens evidence that the virus can spread between people, however experts say the risk to the general population remains small.
Of the 12 people confirmed to have the virus, five have died.
This case appears to be a milder form of the infection and the patient is not being treated in hospital.
The infection is thought to come from contact with animals. However, if the virus can spread between people it poses a much more serious threat.
This is the fourth case identified in the UK. The first was a patient flown in from Qatar for treatment. The second was linked to travel to the Middle East and Pakistan.