"When they were dating I walked into his bedroom and his comforter smelled of women's fragrance," Ms McManus, tells the publication.
"This was not normal. When I began cleaning I saw a white sexy lacy little bra abandoned under the bed."
"There were two broken glasses next to it. I had to clean them up and felt it was Michael playing games with me," Adrian continued.
"It all seemed so set up because that had never happened before. Sure, there were his underpants, shirts and trousers discarded, but nothing belonging to women ever were there."
"I thought that he was trying to make me think that something was going on between him and her. I knew they were dating, but he was trying to make me believe they were sexually close. I always had my doubts.
"From my recollection, she never stayed overnight in his private bedroom.
"Never once did I walk into Michael's bedroom and see them in bed or hanging out.
"On the few times she did stay in the main house, she would stay in The Rose Room. That room was way in the front of the mansion overlooking the flowers, while Michael's quarters were at the downstairs of the rear of the mansion.
"They could not be further apart. I can't even recall Michael ever going to The Rose Room."
The sensational allegations come after the explosive documentary Leaving Neverland was released earlier this year, which focuses on two men, Wade Robson and James Safechuck, who allege they were sexually abused as children by Michael Jackson.
As for Lisa Marie, the American singer remains insistent that she maintained a sex life with Jackson.