Paul Burrell believes Princess Diana knew he was attracted to men.
The 58-year-old former butler to the late royal - who passed away in 1997 after being fatally wounded in a car crash in Paris - is set to marry his male lover Graham Cooper, and says that despite never telling his "best friend" Diana about his sexuality, he says her "good judge of character" meant she probably already knew.
Asked if Princess Diana knew he was gay, Paul said: "I never had that conversation with her. "I was her best friend. I was a great adviser on what to wear and when to wear it. I did great flower arrangements ... it didn't have to be said.
"I think Diana was a very good judge of character too, the Queen wouldn't have chosen me to stand beside her for eleven years, and Diana wouldn't have chosen me for ten years if I wasn't the right person."
And Paul - who divorced his ex-wife Maria last year after spending a decade separated from each other - says he even believes Queen Elizabeth might have known about his sexuality.
He added to UK television show 'This Morning': "I think she might've [my sexuality], I think the Queen is a very astute women and she knows her staff inside out."
The news comes after Paul - who shares sons Nick, 24, and Alex, 27, with his ex-wife - revealed it was Queen Elizabeth herself who told him he should get married in 1994 when he met Maria.
He said: "Her Majesty took me aside and said, 'Paul, the institution of marriage is a wonderful thing - have you thought of getting married?' I said, 'Well, your Majesty, I have, yes'. She replied 'Well there are some lovely girls around the Palace. I'm sure you can find one suitable'.
"Some time later I was in Her Majesty's bedroom and Prince Philip's maid came in to help me. She helped me pull over a cover and smiled at me and I thought, 'How sweet, she's lovely'. That was Maria. We went to Balmoral, very much a party place and somewhere to begin relationships. We got to know each other better and realised we had a great deal in common. I took a picture of her as she was leaving to go back to London. That's the moment I thought, 'Yes, she's the one I'm going to marry'."