She added: “They just adored each other. They saw each other all the time.
“She was what a lot of people call ‘the first time Camilla’ in that she was a real rival to Camilla.”
Angela then described how Charles apparently described Dale, who was married to one of his friends, as one of the only people who properly understood him.
“Perhaps it was just a really close friendship, who knows?” Angela said.
While it remains unclear whether Charles and Dale were ever anything more than just friends, Angela told listeners the pair were nonetheless very close.
The royal revelation comes after it was reported The Crown is set to show some controversial storylines from Charles' life and marriage to Princess Diana in its fourth season.
Actor Josh O’Connor, who plays Prince Charles in the hit Netflix show, said producers are “going to pull the rug from under him” in the forthcoming fourth season.
Describing how the show has been “really nice” to Charles so far, Josh, 29, told Express.co.uk: “Well, it’s the Diana years, so we know that period so well.
“And, in terms of Charles himself, if series three was to make people feel empathy and sorry for him, I guess we’re going to pull the rug from under him in the next series.”