The race is on to track down anyone who has been in close contact with two Chinese nationals who have been diagnosed with the new coronavirus while in the UK.

A specialist outbreak investigation team from Public Health England (PHE) is working to identify anyone who may be at risk from infection to try and prevent the virus spreading further within the UK population.

Close contact has been defined as anyone who has been within two metres of either of the two infected people for at least 15 minutes.

The PHE team will follow the pair's movements and anyone who may be at risk will be told to self-isolate indoors for two weeks and avoid going to work or visiting public places and using public transport.

Anyone who becomes ill will be asked to call the NHS 111 helpline and could then be tested for the virus and if they test positive, officials will begin the process again to trace any contacts.

The coronavirus has now killed 259 people in China and spread to countries around the world.

A key challenge for the PHE specialists will be to find out whether the two infected Chinese citizens, who became ill while staying at a hotel in York, brought the virus to the UK from China or contracted it in the UK from another person.

It is thought the people infected with coronavirus can go on to infect as many as three other people on average.

A total of 83 UK citizens and 27 other people evacuated from the Chinese city of Wuhan were on Saturday beginning a two-week quarantine at accommodation at Arrowe Park Hospital on the Wirral.

Dr Bharat Pankhania, senior clinical lecturer at the University of Exeter Medical School, said: “It’s no surprise at all that we have cases in the UK. As the virus has now spread to remote parts of the world, it was inevitable.

“It’s really positive that the cases have been identified. That means they can be isolated, and the authorities can work to identify both the source and other people they have been in close contact with who may be harbouring the virus, to ensure they isolate themselves and don’t risk spreading infection.

“Although we don’t yet know whether the two relatives picked up the virus from overseas, we can expect further imported cases in the UK which may not be linked with this case, as the virus is now so widespread globally.”

Professor Sharon Peacock, director of the national infection service at PHE, said: “Public Health England is contacting people who had close contact with the confirmed cases.

“Close contacts will be given health advice about symptoms and emergency contact details to use if they become unwell in the 14 days after contact with the confirmed cases.”