When beginning work with Wallace on the book, Kyle said: "The first interview we did was pretty straightforward, and then we agreed to meet whenever he was available."
Kyle, who has written numerous books, alleges that on the “second or third interview”, which had taken place in his own restaurant around 8am to account for Wallace’s “very busy schedule filming”, he “started to talk about his love life”.
“He was dating lots of different women. And he started telling me about these dates, who the women were, where he met them. And then in very graphic details, what sexual acts they had done together,” Kyle said.
"He talked about spanking a lot. He also talked about one of his girlfriends on all fours in front of a mirror. He talked in incredibly sexual detail, which at the time it was just so shocking because it was completely unnecessary for the book."
On one occasion, she said a meeting was arranged at Wallace’s flat, and he opened the door "completely naked, except for a towel around his waist".
Wallace, she claims, said he had just got back from the gym and had a shower and said it would be OK for her to go into the living room.
Kyle said she asked Wallace: "Look, can you just go and get dressed?"
She said that she sat on the sofa while waiting for him. Wallace then returned in the towel and, she claims, said his trousers were folded behind the cushion she was next to.
“Then I kind of looked up and then he dropped the towel,” she said.
Newsnight asked whether the towel dropping could have been an accident, to which Ms Kyle said “definitely not”.
“I felt quite vulnerable because I'm on my own in a flat with a man. He's naked," she said.
Kyle, who was a single parent at the time, had signed a non-disclosure agreement (NDA), before beginning the project.
The NDA said the “writer understands that Wallace enjoys a high public profile and her obligations to him of loyalty and confidentiality are therefore of particular significance".
“I was worried about losing the job,” she said, “because I'd given up all the work for this job. So I thought to myself... I'm just going to try and navigate this, [I’ll] just try and push on through," she said. “It was just really revolting."