Prince Harry claims that King Charles once joked that James Hewitt was his "real father".
The 38-year-old prince has claimed in his new memoir, 'Spare', that the king made a joke "in poor taste" during a visit to a psychiatric hospital, where he met a man who claimed to be the Prince of Wales.
Harry claims that Charles waved his finger at the patient and said, "I am the Prince of Wales", prompting the man to "respond with the same gesture".
According to Harry, Charles then joked: "Who knows if I'm even your real father? Perhaps your father really is in Broadmoor, my dear son!"
Harry believes the joke was made in poor taste because of the widespread rumour that James - Princess Diana's ex-lover - was his actual father.
James, 64, had a five-year affair with the princess, between 1986 and 1991.
Meanwhile, the Duchess of Sussex recently likened her engagement announcement to an "orchestrated reality show".
The 41-year-old former actress and Prince Harry announced their engagement in 2017, and Meghan admits that their photocall and TV interview both felt "rehearsed".
During Netflix's 'Harry and Meghan' documentary series, she shared: "It was rehearsed. We did the thing out with the press, then we went right inside, took the coat off and did the interview. So it’s all in that same moment."
Meghan - who has Archie, three, and Lilibet, 19 months, with Harry - revealed that she was prompted to do and say certain things during the interview.
Meghan also feels that they were stopped from telling their real story.
Asked if she was told how the interview would unfold, Meghan replied: "Yeah, but also like, ‘Then there’ll be a moment where they’ll want to see the ring, so show the ring’ ... We weren’t allowed to tell our story because they didn’t want [it]."
Harry added: "We’ve never been allowed to tell our story."