“Dr Khan loved football, beer and telly,” said Paul.
“I was told to get a huge settee, a massive TV and a fridge full of beer by Diana.
“‘How could he resist that?’ she said.
“She really cared for Dr Khan. She told me, ‘We’re going to have new and exciting times, aren’t we?’”
Dr Khan, 57, shared a two-year romance with Diana and, according to Paul, was adored by the Princess. Their relationship ended just before she died in 1997, aged 36.
Paul says Dr Khan called him last week to discuss a new film on Diana.
“I hadn’t spoken to him since the funeral,” said Paul.
“A film crew had tried to contact him and he didn’t want anything to do with them.”
Paul said the pair agreed to meet for a drink and a talk.
“I’m sure we’ll have a cry together,” said Paul.