The Duke of Edinburgh has been admitted to hospital in London on the advice of his doctor as a precautionary measure relating to a pre-existing condition.

Prince Philip, 98, had been staying on the Queen’s Sandringham estate in Norfolk.

In a short statement, Buckingham Palace said: “The Duke of Edinburgh travelled from Norfolk this morning to the King Edward VII hospital in London for observation and treatment in relation to a pre-existing condition. The admission is a precautionary measure on the advice of his royal highness’s doctor.”

The duke is expected to remain in hospital for a few days.

The announcement came as the Queen arrived on Friday morning from London to Sandringham, where members of the royal family traditionally gather for Christmas.

Prince Philip is said to have walked into the hospital unaided. Aides said he was not transported by ambulance and there were reports that he was taken from Norfolk to London by helicopter.

Palace sources stressed it was a planned rather than sudden admission but it raises the possibility that the prince might not be able to join the rest of the royal family for Christmas Day.

Buckingham Palace would not elaborate on details about the pre-existing condition, or whether Philip was likely to undergo any surgical procedures while in hospital.

Aides said the Queen had travelled to Sandringham by train on Friday morning, and her plans remained unchanged.

In 2011, the duke, then 90, received treatment for a blocked coronary artery. He was taken to Royal Papworth hospital in Cambridgeshire as the royal family gathered for Christmas, after suffering chest pains. He underwent a “minimally invasive” procedure of coronary stenting, involving pushing a balloon into the artery and blowing it up to remove the blockage.

The following year, he missed the Queen’s diamond jubilee concert after being taken to the King Edward VII hospital with a bladder infection. He remained in hospital under observation for several days.

In June 2017, after a day in sweltering conditions at Royal Ascot, he was admitted to hospital as a precautionary measure for treatment for an infection arising from a pre-existing condition, and was discharged after a two-night stay.

In 2018, the duke underwent a hip replacement operation.