Simon Cowell's lifestyle revealed

Simon Cowell enjoys twice-yearly Botox, regular colonic irrigation and intravenous vitamin injections to keep him looking young, according to the unofficial biography of the TV star.

In the latest extract of Sweet Revenge: The Intimate Life Of Simon Cowell, which is being serialised in The Sun, the Britain's Got Talent and US X Factor judge is said to use black loo roll in his bathroom and have a feature in his garden that makes him look as though he can walk on water.

The book, by Tom Bower, said that he has "life-enhancing" fresh fruit sent to him by air freight and drinks two smoothies a day made from exotic plants.

The star also has massages, chest waxes, wears tooth caps and dyes his hair, according to the book, which previously revealed he had a fling with Dannii Minogue.

According to Bower, the TV talent show supremo is put on an intravenous drip in his bedroom every Saturday afternoon, whenever he is in the US, to pump magnesium, B vitamins and pure vitamin C into his bloodstream.

Cowell posted a message on Twitter to point out that this was not an official biography although he did not deny he had taken part in the book's preparation.

He said: "This book is not written by me. It is unauthorised. The writer is Tom Bower."

His publicist Max Clifford told ITV's Daybreak he was "disappointed" that Cowell had agreed to speak to the author.

He said: "We discussed it and I told him to keep well away from Tom Bower, in my view. Once you speak to someone, you're working with them.

"The book hasn't done anything that's going to increase his popularity with anybody. It makes him appear to be someone who talks about his private life. He doesn't."