(Cover) - EN Showbiz - An unauthorised book has detailed the "spark" between Angelina Jolie and Brad Pitt when they first met.

The pair famously starred in 2005 action comedy Mr. & Mrs. Smith together, and reports of chemistry on set led to rumours of a romance.

Brad was married to ex-wife Jennifer Aniston at the time, and has always maintained that his relationship with Angelina began after his split from Jennifer. Although no romance was instigated on set, the book Confidential: The Life of Secret Agent Turned Hollywood Tycoon Arnon Milchan by

Joseph Gelman and Meir Doron describes their instant attraction.

"Milchan introduced Pitt to Jolie and immediately sensed that there was a spark between them," reads the book, according to New York Post.

As well as detailing his former life as an Israeli secret agent, film producer Arnon goes on to make more allegations about Brad and Angelina, who confirmed in January 2006 they were officially an item when Angelina was pregnant with their first biological child together Shiloh, now five.

The pair also raise twins Knox and Vivienne, three, and their three adopted children; boys Maddox, nine, and seven-year-old Pax and six-year-old girl Zahara.

Arnon claims he offered Brad shelter when the actor allegedly got into marital difficulty with then-wife Jennifer.

"When Aniston kicked Pitt out of the house, all hell broke loose," he writes. "When I heard that Brad left home I offered that he stay at my house in Malibu. He drove to the set on a motorcycle, and he wore a wrap-around helmet with a tinted visor so no one could recognise him." (C) Cover Media