Cocaine snorting, adultery and a one-time fling with a future NBA All-Star are among some of the alleged activities Sarah Palin partook in, according to salacious details leaked from a new unauthorized biography about the former Republican candidate for vice-president.

Whether or not they hold true, the claims made in journalist Joe McGinniss's highly-anticipated book, The Rogue: Searching for the Real Sarah Palin, may be politically damaging and could imperil the former Alaska governor's expected bid for the U.S. presidency.

McGinniss moved next door to the Palins in Wasilla, Alaska, from Massachusetts in 2010 to gather research for the biography, which quotes former NBA champion and Miami Heat player Glen Rice confirming a 1987 one-night stand with Palin, according to a story about the book published by The National Enquirer.

Rice was a junior at the University of Michigan playing at a college tournament in Alaska at the time, the supermarket tabloid reported. Palin allegedly met him while she was working as a TV sports reporter for the Anchorage station KTUU.

Cocaine and snowmobiling

The book says the pair had sex once, and Palin married her husband, Todd, nine months later, according to the tabloid.

The Enquirer also reports that McGinniss's book, which is being billed as an exposé, supposedly corroborates previous rumours that Palin had a six-month-long extramarital affair  in the mid-1990s with Brad Hanson, with whom her husband once ran a snowmobile dealership.

As for the cocaine use allegations, McGinniss paints a bizarrely vivid picture: that of Palin snorting coke off an overturned 55-gallon oil drum during a snowmobiling trip with her husband and friends. McGinniss claims Todd experimented frequently with cocaine, the Enquirer reports.

In a blog posting this week, McGinniss blasted the Chicago Tribune, Newsday and Atlanta Journal-Constitution, accusing the newspapers of dropping a Doonesbury comic strip "for a full week because the strip contained quotes from The Rogue."

The book is due for release by Random House on Sept. 20.