Sunday on WOAY: Inside Princess Diana's tumultuous love affair with a heart surgeon before her untimely death

Princess Diana took a trip to Pakistan in 1997 that was officially presented as her doing a favor for close friends to help raise money for a cancer clinic in Lahore.

But privately, royal insiders say the trip was connected to an on-off romance she was having in London with Hasnat Khan, a British-Pakistani heart surgeon whom she called “Mr. Wonderful.”

“She was truly taken with somebody who was so pure of purpose,” said Vanity Fair journalist Sarah Ellison. “He was healing people. He wasn’t remotely interested in her fame. He obviously wasn’t all that interested in his own appearance. He sort of had a paunch. He ate Kentucky Fried Chicken. I mean, it’s definitely this sort of aggressive kind of normalcy.”

Diana and Khan’s relationship is featured in the upcoming ABC special “The Last 100 Days of Diana,” which retraces the events and details of Diana’s final months through the eyes of close confidants until her untimely death in Paris 20 years ago. “The Last 100 Days of Diana” premieres Sunday, May 7, at 9 p.m. ET on ABC.