Hollywood superstar Angelina Jolie spearheaded a smear campaign against her partner Brad Pitt's ex-wife Jennifer Aniston, claims a new book that promises to reveal the "untold story" behind Hollywood's 'It' couple.

Brangelina by Ian Harperlin claims that the 34-year-old Tomb Raider star who now raises a family of six with Hollywood heartthrob Pitt, waged "a mean-spirited but effective campaign" against Aniston, reported a US magazine.

Pitt had divorced the Friends star and soon went public with his relationship with Jolie, but she did not want to be called a "man-stealer" and began to plant press stories to put the onus of the split on Aniston, claims the book.

“Jolie and her camp, including her manager Geyer Kosinski and brother James Haven, planted press stories in 2005 that painted Aniston in a negative light.”

Specifically, that Aniston firmly prioritised her career over starting a family which put her directly at odds with Pitt, who ached for kids," wrote Harperlin.

"She was convinced that this is the story that would resonate with all these women who saw her as a man-stealer," the author added.