Prince Harry attempted to cancel the publication of his memoir after visiting the UK last summer, according to a publishing source in the United States.
Spare is due for release on January 10 but was leaked after the book inadvertently went on sale early in Spain.
The Duke of Sussex's autobiography has delivered a number of bombshell claims about the royal family, from an accusation of Prince William physically assaulting his brother during a row about Meghan Markle, to Harry and William asking their father King Charles not to marry Queen Consort Camilla.