A spokesperson for the Foreign Office said: "We are supporting the family of a British man who has died in Japan and are in contact with local authorities.
"Our sympathies and thoughts are with his family at this difficult time."
Health Minister Jo Churchill has said she was aware a British man who had been on board the Diamond Princess cruise ship was "very poorly".
She told BBC Radio 4's World At One programme: "The Foreign Office are supporting the family of a British man who has been very poorly and was a passenger on board the Diamond Princess.
"I haven't had confirmation, because obviously I'm on the telephone to you, but I was aware there was a gentleman who was very, very poorly, and I'm sure like me your thoughts and sympathies go out to his family at this time."
She added: "It is my understanding this British national doesn’t in fact reside in the UK, but lives elsewhere in the world.
"That makes absolutely no difference to his family. Our sympathies and thoughts are with them at this difficult time.”
A spokeswoman for Princess Cruises, which operates the Diamond Princess ship that the British man had been holidaying on, said: "All of us at Princess Cruises, including the crew of Diamond Princess, offer our sincere condolences to family members and friends for their loss.
"Our dedicated care team are on hand to provide support."
The quarantined ship, off Japan's Yokohama port, has seen more than 600 coronavirus infections.
Earlier a female passenger, reported to be a Japanese woman in her 70s, became the fifth person to die on the ship.
Thirty-two passengers arrived at the Arrowe Park Hospital in the Wirral over the weekend after spending two weeks quarantined on The Diamond Princess.
Four of these tested positive for coronavirus strain COVID-19, it was confirmed.
Professor Chris Whitty, Chief Medical Officer for England said on Sunday: “Four further patients in England have tested positive for COVID-19, bringing the total number of cases in the UK to thirteen.
“The virus was passed on in the Diamond Princess cruise ship and the patients are being transferred from Arrowe Park to specialist NHS infection centres.”
A British vlogger spent more than two weeks aboard the ship in Japan has been creating videos about the conditions on the Diamond Princess after it was forced to go into lockdown in Yomoha.
David Abel and wife Sally, from Northamptonshire, were transferred off the ship and taken to hospital in Japan last week, initially with fears they had contracted the deadly 2019-nCOV strain.
Japan ordered the ship into quarantine after an 80-year-old passenger, who left the vessel in Hong Kong on January 25, tested positive for coronavirus.
The Japanese government was criticised for the way it handled the ship's quarantine, with reports of doctors saying it acted like an incubator.
Asked how close the UK was to cancelling big events due to the the virus, Ms Churchill said: "We are taking the advice of the Chief Medical Officer and assessing the situation on a day-by-day basis.
"Any decision to cancel events or mass gatherings have to be assessed at the time, based on clinical guidance and based on risk."
Boris Johnson is under fire for waiting until next week to chair his first meeting of the Government's Cobra contingencies committee on the coronavirus outbreak.
Downing Street announced the Prime Minister would head the meeting of ministers and senior officials in Whitehall on Monday.
A No 10 spokesman said this followed the sharp increase in the number of cases of Covid-19 in mainland Europe – prompting fears it is only a matter of time before they start rising in the UK.
But Labour again accused Mr Johnson of acting as a "part-time prime minister", saying he should be taking action immediately to take control of the situation.
Shadow health secretary Jonathan Ashworth said: "Our part-time prime minister needs to get a grip of this escalating situation quickly.
"It shouldn't take another three days for this meeting to take place."
Downing Street said officials from the Department of Health, Public Health England and other relevant departments were meeting on a daily basis to discuss the crisis, while Health Secretary Matt Hancock had been chairing a weekly Cobra meeting.
Those will now be stepped up to take place twice weekly.
"The Prime Minister is keen to chair Cobra on Monday to ensure that everything that can be done is being done," the spokesman said.
The spokesman also disclosed that Mr Johnson had spent half of the night shift on Thursday visiting Kettering Hospital where senior clinicians had talked him through their preparations.
The rapid spread of coronavirus raised fears of a pandemic on Friday, with five countries reporting their first cases, the World Health Organisation warning it could spread worldwide and Switzerland cancelling the giant Geneva car show.
Hopes that the epidemic that started in China late last year would be over in months have been shattered as the number of international cases has spiralled.
"The outbreak is getting bigger," WHO spokesman Christian Lindmeier told a news briefing in Geneva.
"The scenario of the coronavirus reaching multiple countries, if not all countries around the world, is something we have been looking at and warning against since quite a while."
Switzerland joined countries banning big events to try to curb the epidemic, forcing cancellation of next week's Geneva international car show, one of the industry's most important gatherings.
The United States asked its military in Saudi Arabia to avoid crowded venues including malls and cinemas.
Mainland China reported 327 new cases, the lowest since January 23, taking its tally to more than 78,800 cases with almost 2,800
China's three biggest airlines restored some international flights and the Shanghai fashion show, initially postponed, went ahead online.
Mirror Online has contacted the Foreign Office about the latest death and is awaiting comment.
We'll be bringing you the very latest updates, pictures and video on this breaking news story.