A second person in the UK is feared to have died from coronavirus, Sky News understands.
The man was understood to be in his late 80s, had underlying health conditions and died at Milton Keynes Hospital.
Doctors are awaiting official test results to confirm if it was a case of COVID-19.
Other patients on the ward were isolated this morning while a deep clean was carried out, Milton Keynes Citizen reported.
Hospital staff who nursed the patient are also said to have gone into isolation.
A detailed contact tracing exercise is now being conducted to trace anyone who came into contact with him in the days before his death.
Forty-eight new coronavirus cases have been confirmed in the UK over the past 24 hours, taking the total to 164.
On Thursday, a woman reported to be in her 70s became the first person in the UK to die after being diagnosed with coronavirus.
The Royal Berkshire Hospital in Reading said the woman had been "in and out of hospital" for other reasons but was admitted on Wednesday evening and tested positive.
Meanwhile, two British Airways staff tested positive for coronavirus on Friday and are recovering at home in isolation.
"Public Health England (PHE) has confirmed that two members of our staff have tested positive for the COVID-19 virus," it said in a statement.
Also, Facebook is closing its London offices until Monday and telling staff to work from home after an employee was diagnosed with COVID-19.
The employee who was diagnosed with the virus was normally based in Singapore, the company told Sky News, but had visited the London offices between 24-26 February.
Globally, the number of coronavirus cases has passed 100,000, with 3,400 deaths, and the virus has spread across more than 90 nations.
In other developments:
Prime Minister Boris Johnson has visited a Bedfordshire laboratory as the government pledged an extra £46m for research into a vaccine and rapid diagnostic tests.
The government is working with supermarkets to ensure food supplies as the number of people self-isolating with the virus continues to rise, Health Secretary Matt Hancock said.
He sought to reassure the public following panic-buying in some areas, saying the government is "working to makes sure that if people are self isolating, they will be able to get the food and supplies that they need."
He added there was "absolutely no need" for individual people "to go round buying more than they need."
Health chiefs said people diagnosed with coronavirus who show only "very minimal" symptoms should self-isolate at home rather than in hospital.
Travellers returning to the UK from anywhere in Italy have also been advised to self-isolate if they develop symptoms.
Last week, a British tourist who had been on board the Diamond Princess cruise ship, which was quarantined in Japan, became the first UK citizen to die from the virus.
Professor Chris Whitty said half of all coronavirus cases in the UK are most likely to occur in just a three-week period, with 95% of them over a nine-week period.