Paul Burrell thought Princess Diana was "playing a trick" on him during her final moments.
The former butler to the late Princess of Wales - who died in car crash in 1997 aged 36 - couldn't believe she was dying, and now wishes Diana had taken him with her when she passed away.
He recalled: "When she died, I sat with her, I held her hand and I said to her, 'Wake up, wake up, you're not really dead are you? You're still alive and you're playing a trick on me'.
"She didn't open her eyes and I said, 'Why did you leave me here? Why didn't you take me with you? Because my place is to look after you.' "
Paul admitted he is beginning to forget the sound of the princess' voice and her scent, and wishes he could hear her voice again.
Speaking on 'I'm A Celebrity... Get Me Out Of Here! Australia', he added: "For a long time I couldn't let go of that because as time passes she will fade. I'm beginning to forget what her voice sounded like. And forget what she smelt like. I don't want to forget that.
"The last thing she said to me, we were on the phone, she was in Paris, and the very last words were, 'Promise me you'll always be there.' "
In August, Paul revealed he slept in Diana's wardrobe after she died and would sit next to her "soft and warm" corpse.
Before her passing, Paul used to help her battle bulimia by giving her "a gallon of custard".
He said: "I'd help her with that. I'd get the chef to prepare a gallon of custard and I'd buy yoghurts and lots of bananas. And I'd prepare the room for her to make sure she was comfortable.
"Make sure there was a pile of towels ... I was doing my duty. I would have done anything for Diana.
"I wasn't able to challenge what was happening.
"I couldn't tell her what to do. I could be there, I could put my arm around her."
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