When Montreal-born author Ian Halperin first set out to write the definitive Michael Jackson biography, his intention was to nail the pop icon to the wall.

It was 2005 and Jackson had just been acquitted of a second charge of child molestation.

By the time Halperin, 44, finished the book, and long before Jackson died two weeks ago, his opinion of the troubled artist had undergone a 180-degree shift.

"I interviewed all kinds of people connected to the case and kids who stayed at NeverLand, and my final conclusion today is that he is 100 per cent not a child molester," Halperin said in an exclusive interview with The Gazette this week.

Rather it was Jackson's childlike attitude toward both his business dealings and his personal life that were his undoing, Halperin said.

As fate would have it, Halperin's book was ready to go to the presses one day before Jackson died on June 25.

After some furious rewrites and a change of title, Unmasked: The Final Years of Michael Jackson will hit bookstores on Tuesday.