The man convicted of killing Michael Jackson claims the King of Pop was chemically castrated in a new book he says the King of Pop wanted him to write.

Conrad Murray served two years in jail for manslaughter after giving Jackson propofol to help him sleep.

To this day he maintains he didn't do it though, and has now told all in a new book, This Is It!: The Secret lives of Dr. Conrad Murray and Michael Jackson.

Murray also claims no one should have left their children with Jackson, even though the popstar wasn't the paedophile many claimed he was.

"He's a heterosexual man, but heinous things happened to Michael in his lifetime that actually changed, or had him morph into who he thought he was."

One of those things, according to Murray, was his parents arranging for his chemical castration.

"His testes were never removed, but injections were given to Michael Jackson to maintain his voice, his high-pitched voice of a child that went long beyond puberty."

He places much of the blame for Jackson's extraordinary, but difficult, life at the feet of his family.

"They never cared about Michael Jackson. Michael Jackson was a tool. He knew that he was not loved... They would rather have the real story of Michael buried with him, but that will not happen. The book is out, the truth is told and now it's history."

Murray says he wrote the book because the late singer wanted people to know about his life.

"He was stating should anything happen to him, should he die... he wanted his story to be told," Murray told Paul Henry on Friday.

"He asked me if I would do this - I [said] yes, but I never thought it would come to this as a reality. I thought he and I would grow to be old men together, and look back... and reminisce more on the fun times."

As we know now, that never happened. On June 25, Murray found Jackson in his bed. He was rushed to hospital, but later died.

Murray was charged and found guilty of being giving Jackson lethal amounts of propofol and benzodiazepines. Murray says there has never been proof he did so, and that it would have been "total madness" to deliver the fatal dose of propofol because Jackson was already passed out at the time.

"Up until today they have not been able to provide the level of propofol in Michael's brain because it was not there."

Even so, Murray says if he had known the extent of Jackson's drug use and abuse, he would have treated his patient differently - or have left him to his own devices.

"I would have enrolled him in rehab and I would have gone with him, because I cared about him that much. But Michael also knew I had an aversion to drug addiction. Even though I'm a physician, I'm sorry about that. I'm not against drug addicts - I know it's a real disease - but I like to stay away as far as possible from that type of element.

"Michael knew that I would leave his side if he declared that. I believe it is that fear in him, he was not able to divulge in me that habit."