Writer Tom Bower is planning a sequel to his revealing biography of Simon Cowell – and he said the X Factor boss has already agreed to talk to him.

Bower’s unauthorised book was assembled from hundreds of hours of conversations with the media mogul.

The journalist said Simon had conceded some of the revelations were ’embarrassing’, but they ‘remain friends’.

The biography, Sweet Revenge, detailed the millionaire TV and music boss’s affair with Dannii Minogue and unflattering comments about X Factor judges and contestants as it gave an insight into his life.

He told ITV1’s This Morning that he had spoken to Simon since the contents became public.

“The first call was ‘you are getting a lot of publicity for your book’. He said ‘it’s a bit embarrassing, you got things I didn’t know you’d got’. But we get on very well. Finally he said to me last night, ‘we remain friends.'”

Bower said he was contacted ‘out of the blue’ by Simon when he heard he was working on a book about him and agreed to co-operate.

“It was a very, very interesting journey. There is a man who’s actually very private in his life although he doesn’t seem it. He keeps his secrets pretty well.

“I flew with him a lot to America on his private jet, I was on his yacht, visited him often in his house in LA. I got to know him very well and we got on very well. In the end I reported what I found.”

He said there would be enough material for a second book. “Oh yes, there will be a sequel,” Bower confirmed.

Asked whether Cowell would speak to him for the follow-up, he said: “I think he will. He said last night that he will.”