Buckingham Palace has forcefully denied a claim by the brother of the late Princess Diana that King Charles III said she would soon be forgotten after her death.

In a new book, Charles Spencer recounts the traumatic days after Diana was killed in a car crash in Paris in 1997 at the age of 36. He alleges that he argued with the then-Prince Charles, Diana's estranged husband, over palace plans for Prince William and Prince Harry to walk behind her coffin during the funeral procession.