Yet despite a series of meetings between the Duke of Cambridge’s aides and the BBC, they are determined that the “investigation” will not be shown to courtiers.

It is unclear whether the Duke and Duchess of Sussex have raised any concerns about the show or were contacted before the other households complained.

A senior royal source told the Mail on Sunday that the Queen was “upset” that the “tittle-tattle” documentary would air without anyone at the Palace having a chance to see it.

It is the second time the Royals have intervened over coverage of the rumoured feud between the Duke of Cambridge and his brother, the Duke of Sussex.

Earlier this year, just hours before the documentary Harry And William: What Went Wrong? was due to broadcast, ITV removed claims by Omid Scobie, the Duke and Duchess of Sussex’s biographer, that Prince William and his staff planted a story about Prince Harry’s mental health.

There is concern that the BBC documentary may repeat similar allegations, which have been consistently denied by the brothers.