A British passenger on board a cruise ship has tested positive for coronavirus.

Princess Cruises said an additional 41 people, including the Briton, had tested positive for the virus on the Diamond Princess, which is quarantined off Yokohama in Japan.

The British passenger is Alan Steele, from Wolverhampton, who posted on social media that he had been diagnosed with the virus.

READ MORE: Coronavirus: World Health Organisation declares global health emergency

Mr Steele, who is believed to be on his honeymoon, posted on Facebook that he was not showing any symptoms but was being shipped to hospital.

A British man is among 41 confirmed coronavirus cases aboard a quarantined cruise ship anchored off Japan(PA Graphics)

He added: “Just to let you all know I have been diagnosed as having the virus and am being shipped to hospital.

“Would also like to say that at the moment I am not showing any symptoms so just possible a carrier.

“Will let you know how I am going on when possible.”

The announcement comes after a third person in the UK was diagnosed with coronavirus, and is believed to have caught the illness in Singapore.

It has been reported that this third patient is a middle-aged British man who is understood to be the first UK national to contract the disease.

READ MORE: Two positive cases of coronavirus confirmed in UK

A fellow passenger on the Diamond Princess said the British man who tested positive for the virus was on his honeymoon and will be separated from his new wife as he is taken off the ship for treatment.

David Abel said in a video update posted on Facebook that he had been dining with the man, who was not named.

He added: “He will almost certainly be leaving the ship today – real, real shame.

“I have no idea how he must be feeling … they’re on their honeymoon.

“He will be going off in to quarantine in a medical facility and she has to stay on board the ship because she’s not displaying symptoms.

“That’s going to be really, really tough for him so just bear a thought for these passengers who just don’t know what is going to be lying ahead of them.”

Princess Cruises said the quarantine on the ship was due to end on February 19, barring “unforeseen developments”.

The company also confirmed that all the affected guests were being taken to hospital.

The additional 41 cases takes the total number of people diagnosed with the virus on board the cruise ship up to 61.

In a statement, the company added: “Princess Cruises can confirm the nationalities of the 41 people who were tested positive for coronavirus are from Argentina (one); Australia (five); Canada (five), Japan (21); United Kingdom (one) and United States (eight).”

The latest diagnoses comes as as health experts issued a new warning to travellers arriving from several Asian countries.

There are 78 people with British passports – including crew – on the Diamond Princess cruise ship, sources told the PA news agency.

There are no plans to fly anyone from the ship and back to the UK at the moment.

The third patient to be diagnosed with coronavirus in the UK is thought to have been diagnosed in Brighton and was transferred to St Thomas’ Hospital in London, where there is an infectious disease unit, on Thursday afternoon.

HEALTH Coronavirus(PA Graphics)

Two other patients are still being treated at the Royal Victoria Infirmary infectious diseases centre in Newcastle.

One is a student at the University of York while the other is a family member.

They had travelled from China in the days before their diagnosis.

The Government is now urging travellers from countries including Thailand, Singapore, Japan and South Korea to self-isolate if they begin to feel unwell.

Other countries on the list are Hong Kong, Taiwan, Japan, Malaysia, South Korea and Macau, as well as mainland China.

Anyone arriving from these locations should stay indoors and avoid contact with other people if they develop symptoms such as a cough, fever or shortness of breath, the advice warns.

Officials in protective suits talkOfficials in protective suits talk near the cruise ship Diamond Princess (Eugene Hoshiko/AP/PA)

Until Thursday, this advice only related to people travelling from Wuhan in China.

The UK Foreign Office has advised Britons in China to leave if they are able to.

More than 80 UK citizens and family members who were the first to be quarantined at Arrowe Park Hospital on the Wirral have been told they can leave next Thursday.

The group are spending 14 days in isolation but will be released next week as long as they remain symptom-free.

A separate ship in Hong Kong, the World Dream, has about 66 British passport-holders on board, officials told PA. Nobody on that ship has tested positive.

PA understands that passengers are unable to leave the ship but are not in quarantine and can move around freely on board.

The global death toll from coronavirus rose to 636 on Friday, with the number of confirmed cases rising to 31,161. Some 260 cases have been recorded outside China.

HEALTH Coronavirus(PA Graphics)

It emerged on Thursday that the Chinese doctor sanctioned by the authorities for issuing an early warning about the coronavirus has died from the illness.

The Wuhan Central Hospital said on its social media account that Dr Li Wenliang, a 34-year-old ophthalmologist, was “unfortunately infected during the fight against the pneumonia epidemic of the new coronavirus infection”.

Mr Li was reprimanded by local police for “spreading rumours” about the illness in late December, according to news reports.

Meanwhile, a newborn baby has become the youngest to be diagnosed with the disease.

Only a handful of children have come down with the new coronavirus, which has been most severe in older people.