Did Princess Diana have 'secret daughter? Book reveals

Princess Diana is said to have a secret child with King Charles in a bizarre conspiracy theory.

The late Princess of Wales seemingly underwent a fertility test to ensure she could give birth to a heir. One of her eggs was then fertilised and led to a bit of a baby girl.

“The royal family has been a magnet for conspiracy theories, in part because they occupy the top position in our society and yet are shrouded in a degree of mystery and ancient ritual,” says investigative historian Tony McMahon, author of the book The Knights Templar. “The pomp and ceremony set them apart from the rest of us and so, unsurprisingly, some people have deduced they must be shapeshifting aliens! Their aloofness is because they are not actually human.”

The story has been published by writer Nancy E. Ryan in 2011, The Disappearance of Olivia, a fictional book on the Royals.

“Given the dynastic nature of the royal family, a story like this is almost bound to arise,” McMahon says. “We know that the ancestors of King Charles were fixated on the importance of having a healthy heir. To what lengths might the royals go to ensure this happens?”