A controversial biography of Sarah Palin claims that she snorted cocaine off a 55-gallon oil drum, and cheated on her husband with his business partner and a basketball player.

The Rogue: Searching for the Real Sarah Palin by Joe McGinnis is scheduled for publication in the US next week.

It alleges that the former Republican vice-presidential candidate was seen snorting cocaine off the top of a 55-gallon drum while snowmobiling with friends, and that she smoked marijuana with a professor while studying at Mat-Su College in Alaska.

The book also resurrects allegations that she had a six-month long affair with her husband's business partner, Brad Hanson, in 1996. Both Palin and Hanson have strenuously denied this in the past.

McGinnis angered Palin by moving in next door to her in Wasilla, Alaska, while he was researching the book. Palin's camp has not yet given an official statement, but her husband Todd Palin said:

This is a man who has been relentlessly stalking my family to the point of moving in right next door to us to harass us and spy on us to satisfy his creepy obsession with my wife. His book is full of disgusting lies, innuendo, and smears. Even the New York Times called this book 'dated, petty,' and that it 'chases caustic, unsubstantiated gossip.

Even ahead of the book's release, the handling of the allegations has caused controversy in the US. McGinnis made a deal with Garry Trudeau, author of the popular Doonesbury cartoon, to include extracts in the comic strip.

Some papers have decided not to run a strip containing the allegation that Palin once spent the night with basketball star Glyn Rice, saying that it is currently unsubstantiated. Another strip which many declined to run claims "Palin isn't comfortable in the presence of dark skinned people".

McGinnis's claims are certainly headline-grabbing, but it is difficult to judge their veracity. A New York Times blog points out that "many episodes cited in the book relied on unnamed sources or second- or third-hand accounts". Some US commentators have suggested that Palin -- a skilled media operator -- will turn this around and garner sympathy from her supporters. With the questionable credibility of the claims -- and the nasty, personal tone that book reviewers have noted -- this could be an effective strategy. There is little doubt the book will be a best-seller, but it remains to be seen whether the allegations will stick.