The source spoke exclusively withIn Touch Weekly, telling the outlet that Charles has pancreatic cancer.
“Many courtiers believe Charles' cancer is worse than they’re making it out to be.
Even before the diagnosis, there were concerns about his health,” they explained.

The royals spoke about the king’s health while making public appearances.
While there, a shop assistant wished the Royal family the best and even gave her a card.
He was very disappointed he couldn’t come" (viaHello Magazine).

Thankfully, at least that whisper was proven false.