The Duke of Cambridge has said the Duke of Edinburgh is "OK" after his 99-year-old grandfather spent a sixth night in hospital.
Prince William was asked about Prince Philip's health during a visit to a COVID-19 vaccination centre in Norfolk.
At the end of his tour of the inoculation hub, set up in the King's Lynn Corn Exchange, the Prince was quizzed about Philip and replied: "Yes, he's OK, they're keeping an eye on him."
There will be concerns about Prince Philip, who is now into his seventh day at the private King Edward VII's Hospital in central London.
Having received his coronavirus jab in January, the Duke of Edinburgh was admitted on Tuesday evening as a precautionary measure after feeling unwell and walked into the building unaided.
Prince Philip was initially due to spend a few days under medical care for "observation and rest" for an undisclosed reason, which is not coronavirus-related.
He received a visit from the Prince of Wales on Saturday.
Last year, he handed over his role as Colonel-in-Chief of The Rifles to the Duchess of Cornwall during a rare public appearance.
Cover image: Prince Philip during his final public engagement in 2017 (Picture: PA).