United Kingdom

Charles II had loads, but they didn't get considered for succession (one, the Duke of Monmouth, did try a rebellion against James II, Charles' younger brother, resulting in the last battle on English soil at Sedgemoor, but he had to fight, not just inherit). George IV was rumoured to have some, but they weren't considered for the throne.

The law controls the inheritance of the crown far more than it does for monetary inheritance for the rest of us. I haven't heard of this man, and it seems unlikely that Camilla could have given birth without it being generally known, but whenever it was supposed to have happened, it wouldn't change things.