Prince Philip almost died "twice" after undergoing secret heart surgery in 2021, according to a new book.

Queen Elizabeth's late husband was taken ill in early 2021 and was admitted to a hospital in London for tests before being transferred to another medical centre to undergo an operation - and the doctors "nearly lost him twice".

Royal historian Hugo Vickers makes the claim in his new book Queen Elizabeth II, writing: "The Duke of Edinburgh, then aged 99, was admitted to the Edward VII Hospital in London for tests.

"On March 1, he was moved to St Bartholomew's Hospital, where he had an operation on his heart. His medical team nearly lost him twice."

Philip survived the scare but his health never recovered and he passed away in April 2021 at the age of 99.

Vickers writes that Philip's heart surgery took place just six days before Prince Harry and his wife Meghan, Duchess of Sussex made a series of bombshell claims about the royal family in a TV interview with Oprah Winfrey, which was broadcast in the US on March 6 2021 and a day later in the UK.

In the book - - which has been serialised by the Daily Mail newspaper - Vickers also claimed Philip had been secretly battling pancreatic cancer for eight years before his death.

The tome also detailed the former Duke of Edinburgh's final days in Windsor Castle. Vickers wrote: "On the last night of his life, he [Philip] gave his nurses the slip, shuffled along the corridor on his Zimmer frame, helped himself to a beer and drank it in the Oak Room.

"The following morning, he got up, had a bath, said he did not feel well and quietly slipped away. By this point, he had lived with pancreatic cancer for nearly eight years - far longer than the usual survival time from diagnosis.

"The Queen was not there when he died. There had often been times in earlier days when she had asked the staff to let her know when Philip was leaving, only to be told: 'His Royal Highness left 20 minutes ago' ... [She was] absolutely furious that, as so often in life, he left without saying goodbye".

Queen Elizabeth died the year after her husband in September 2022.