The singer, who died of heart failure in June aged 50, was also convinced that he could have cured the Nazi leader's evil, had he been alive to speak to him.

He said that the dictator - responsible for the murder of 6 million Jews - needed "help" and "therapy".

Jackson made the claims during interviews with Rabbi Shmuley Boteach, with whom he became close friends. The conversations were recorded with Jackson's approval and have been published in a new book – The Michael Jackson Tapes – which goes on sale in the US and online on Friday.

During one interview, Jackson said: "Hitler was a genius orator. To make that many people turn and change and hate, he had to be a showman and he was."

Boteach then asked the star: "You believe that if you had an hour with Hitler you could somehow touch something inside of him?"

Jackson replied: "Absolutely. I know I could."

He went on to argue that nobody is totally evil, adding: "You have to help them, give them therapy, teach them that somewhere, something in their life went wrong."

Boteach, 42, who recorded more than 30 hours of interviews with Jackson, told The Sun: "Michael despised what Hitler had done. When it came to believing he could heal Hitler, that was hopeless naïvety."