Palace hits back over Charles Spencer's claim about Princess Diana - ABC News & Headlines – Australian Broadcasting Corporation

The allegations are made in the book Swan Song: Diana, My Sister. (Reuters: Kimimasa Mayama)

King Charles has responded to criticism by the brother of his late first wife, Diana.

Charles Spencer alleges in a soon-to-be-published memoir that the then-Prince Charles told him, "Rest assured, we'll forget her soon enough", according to a report in the Daily Mail.

The comment was allegedly made during the arrangements for Diana's funeral.

King Charles III has taken the unusual step of responding to criticism from the brother of his late first wife, Diana, saying via a spokesperson that grief can affect reason, judgement, and memory.

The assertions, made in a soon-to-be-published book, Swan Song: Diana, My Sister, concern the now-monarch's conduct in the days after Diana's death in 1997.

Diana was killed at the age of 36 when the car carrying her and Dodi Al-Fayed crashed in Paris as it sped away from chasing paparazzi photographers on motorbikes.

Her brother, Charles Spencer, alleges that the then-Prince Charles told him, "Rest assured, we'll forget her soon enough", according to a report in the Daily Mail, which begins serialising the book on Thursday, local time.

The reported comments were made in an argument over whether Diana and Charles's children, princes William and Harry, should walk behind her coffin during her funeral — something Earl Spencer objected to, the report said.

Diana became the most photographed woman in the world after marrying Charles in a glittering ceremony in 1981. However, the marriage soured, and the couple divorced in 1996.

Before the book's release, Earl Spencer said: "The aim of this book is to tell the truth about Diana from her brother's perspective … I want to speak on Diana's behalf and do so in an openly positive way."