The Politician, an insider account of former US vice-presidential candidate John Edwards' extra-marital affair with his campaign videographer amid the 2007 nomination campaign, has become online bestseller in the US.

Released last week, the book by Edwards' former aide Andrew Young gives a colourful account of the former senator's sexual encounters with his mistress Rielle Hunter and his attempts to keep the affair under wraps after she became pregnant.

After denying it for more than a year, Edwards finally admitted last month that he fathered Hunter's daughter. The extramarital affair was exposed by the tabloid National Enquirer in October 2007, but Edwards kept denying it.

When Hunter gave birth to her daughter, Edwards pressured the author to admit that he had fathered the child.

Now Young, who worked for Edwards for about 10 years, lays bare his boss' infidelities in The Politician: An Insider's Account of John Edwards' pursuit of the Presidency and the Scandal That Brought Him down" - already online bestseller.

Young writes that after pressuring him to admit that he (Young) fathered Hunter's child, Edwards sent them all - Young, his family and his mistress - on expensive vacations to ward off adverse publicity as he tried to win Democratic Party's nomination for the 2008 presidential elections.

In the book, Young recounts Edwards' mistress narrating their sexual encounters to him.

According to the newspaper, the book portrays Edwards' mistress "as a loose cannon with sex on her mind. Her affair with Edwards lasted, according to Young, for many months before a story about it appeared in the tabloid The (National) Enquirer."

Young narrates how he always carried a special phone for Edwards to talk to his mistress even as his wife Elizabeth's cancer worsened.

The book makes mention of a special video of Edwards' sexual encounter with his pregnant mistress. The author say he found the video in a box of videotapes belonging to the mistress.

In the box, one videotape was marked "special, which had the tape pulled out and seemed intentionally broken... I couldn't resist. With scissors, a pen, and some scotch tape, I fixed the cassette.... As I pressed play, we saw an image of a man - John Edwards - and a naked pregnant woman, photographed from the navel down, engaged in a sexual encounter," the newspaper quoted the author as saying in the book.

"The images were recorded with the somewhat steady assurance of a professional, and the senator's performance was ironically narcissistic... As compromising images of a former presidential candidate and current contender for vice president flashed on the screen, [Young's wife] Cheri and I dropped to the floor, and watched, speechless.... We debated turning it off, but neither of us could actually press the button. It was like watching a traffic pileup occur in slow motion - it was repelling but also transfixing."

This dirty video, says the author, became an important tool in his hands to expose the double life of his former boss.

Edwards, who once championed family values, separated from his wife Elizabeth last month after admitting he fathered the child of his mistress
 

(malathi)