Queen Elizabeth is said to have thought Princess Diana was "far better suited" to Prince Andrew than his brother Prince Charles

Royal expert Ingrid Seward makes the claim in her new book 'My Mother and I', about the now-King Charles' relationship with his late mother.

The book states Diana went to huge lengths to impress on the royals how much she loved the "magical" surroundings of the Queen's beloved Balmoral estate in Scotland "beyond imagination", and said she loved fishing and shooting.

But it adds about the Queen's reservations about Diana's romance with Charles: "She wondered whether anyone that young could differentiate between the man and the prince.

"And she couldn't help thinking that the Spencer girl would be far better suited to her younger son, Andrew."

Diana, born Diana Frances Spencer and who was killed aged 36 in August 1997 in a Paris car smash, is also said in the book to have "determinedly" set out to be the Princess of Wales.

Charles, 75, divorced Diana in 1996 after their notoriously stormy marriage and married the now-Queen Camilla, 76, in 2005.

Prince Andrew's reputation has never recovered from his relationship with billionaire paedophile Jeffrey Epstein or the allegations made against him by one of Epstein's sex trafficking victims, Virginia Giuffre, that the royal slept with her when she was 17.

Andrew has vehemently denied all claims made against him by Virginia.

Ingrid's book is out on 15 February and is billed as "a vivid and revealing portrait of the real relationship between King Charles III and his mother".

A blurb for the biography says: "The relationship between the late monarch and her son, the King, has long been a subject of fascination... this is the story of how Charles was shaped and moulded by his heritage.

"His mother was the woman he loved but could never be close to, and it wasn't until his mother's old age, he finally received the affection and respect from her he had craved for so long."