The Duke of Edinburgh has been tranferred to another hospital from King Edward VII's for testing and treatment.
In a statement released on Monday, the palace said: "The Duke of Edinburgh was today transferred from King Edward VII’s Hospital to St Bartholomew's Hospital where doctors will continue to treat him for an infection, as well as undertake testing and observation for a pre-existing heart condition.
"The Duke remains comfortable and is responding to treatment but is expected to remain in hospital until at least the end of the week."
Prince Philip, 99, spent 13 nights at King Edward VII's hospital in London after being admitted on 16 February as a "precautionary measure" after feeling unwell.
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It comes after a patient was spotted being taken away in an ambulance from the hospital treating the Duke of Edinburgh on Monday.
The patient at King Edward VII's hospital in central London was screened from press and broadcast cameras by umbrellas.
St Bartholomew's Hospital is described on the Barts Health NHS Trust website as an "internationally-renowned" hospital which is a "centre of excellence for both cardiac and cancer care".
It adds that Barts Heart Centre is Europe's largest specialised cardiovascular service.
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Charles visited his father in hospital
On Tuesday 24 February, the palace gave a brief update about the Duke's health, saying that he was receiving medical attention for an infection.
The Queen and Prince Philip's youngest son, Prince Edward, also spoke about his father during an interview with Sky News, saying that the Duke was "looking forward to getting out".
He thanked the public for their well wishes, saying: "We've had some brilliant and lovely messages from all sorts of people and we really appreciate that and so does he, I've been passing them on. It's fantastic, thank you."
The Prince of Wales visited his father in hospital on 20 February, making a 200-mile round-trip from his home, Highgrove, in Gloucestershire.
The Queen and Prince Philip pictured on the Duke's 99th birthday
The Duke of Edinburgh, who will mark his 100th birthday on 10 June, retired from public duties in 2017.
He and the Queen have been spending lockdown at Windsor Castle, although prior to the coronavirus outbreak, Prince Philip had resided mostly at Wood Farm on the Sandringham estate in Norfolk during his retirement.
The Duke carried out a rare public engagement last July, handing over the role of Colonel-in-Chief of The Rifles to the Duchess of Cornwall virtually.
Philip took part in a ceremony at Windsor Castle, while Camilla, 73, was at Highgrove House in Gloucestershire.
Prince Philip during a rare public engagement in July 2020
He and the Queen also attended Princess Beatrice's wedding to Edoardo Mapelli Mozzi in Windsor in July 2020 and were photographed beaming proudly at the newlyweds in the official photographs.
The couple welcomed their ninth great-grandchild in February with the arrival of Princess Eugenie and Jack Brooksbank's son August.
Princess Eugenie confirmed the full name of her baby son as August Philip Hawke Brooksbank, including a sweet tribute to her grandfather.
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