A patient diagnosed with the Sars-like coronavirus has died at Queen Elizabeth hospital in Birmingham it was confirmed today.
The patient died yesterday morning whilst being treated in the hospital's critical care unit, University Hospitals Birmingham NHS Foundation Trust said.
Of the twelve people in the world known to have been infected with the disease half have now died.
Last week it was reported that a second relative of a UK patient who recently contracted the virus had become infected with the disease, taking the total to three within a single family.
On Wednesday, a relative of the first patient became infected and the HPA said a third person, who had not travelled recently was also infected.
The second family member was thought to have an existing medical condition that might have made them more susceptible to respiratory infections, the HPA said last week
According to reports the patient who died today was undergoing treatment for a "long-term complex unrelated health condition" before contracting the new virus.
In a statement confirming the death, the QEHB said the patient was believed to have contracted the virus from a relative who is being treated at a hospital in Manchester.
The statement, issued by the NHS Trust which runs the QEHB, added: "The hospital extends its sympathies to the family.
"The patient was already an outpatient at QEHB, undergoing treatment for a long-term, complex unrelated health condition.
"The patient was immuno-compromised and is believed to have contracted the virus from a relative who is being treated for the condition in a Manchester hospital."
The person is believed to have contracted the disease from a relative in what was the first case of human to human transition of the virus in the UK.
In a statement issued on Friday, the HPA confirmed that four cases of novel coronavirus - including three "in a family cluster" - had been diagnosed in the UK.
Professor John Watson, head of the respiratory diseases department at the HPA, said: "If novel coronavirus were more infectious, we would have expected to have seen a larger number of cases than we have seen since the first case was reported three months ago.
"We would like to emphasise that the risk associated with novel coronavirus to the general UK population remains very low."
In one of the first published studies about coronavirus, or NCoV, which was unknown in humans until it was identified in September 2012, researchers today said it could penetrate the lining of passageways in the lungs and evade the immune system as easily as a cold virus can.
This shows it "grows very efficiently" in human cells and suggests it is well-equipped for infecting humans, said Volker Thiel of the Institute of Immunobiology at Kantonal Hospital in Switzerland, who led the study.
NCoV was identified when the World Health Organisation issued an international alert in September saying a completely new virus had infected a Qatari man in Britain who had recently been in Saudi Arabia.