(Reuters) - Former Alaska Governor Sarah Palin threatened on Monday to sue the author and publisher of an unflattering biography she said was filled with "lies and rumors presented as fact." The book by veteran political writer Joe McGinniss, "The Rogue: Searching for the Real Sarah Palin," was published last week as speculation mounted about whether the Republican conservative firebrand would launch a late bid for her party's presidential nomination in 2012.
A letter from Palin's lawyer said McGinniss and Crown Publishing faced possible legal action for defaming the 2008 Republican vice presidential nominee.
The letter advises the author and Crown to refrain from destroying any e-mail correspondence that might serve as evidence in such a lawsuit. Crown is owned by German-based media conglomerate Bertelsmann AG.
"This book contains a series of lies and rumors presented as fact and combined with 'anonymous' sources," said the letter, sent by Palin attorney John Tiemessen.
As evidence of the malice a successful defamation suit would likely have to show, the letter cited an e-mail from McGinniss to an Alaska political blogger in which he expressed skepticism about unsubstantiated reports pertaining to Palin's personal life that Tiemessen said were included in the book.
"The final work that was published contains most of the stories that Mr. McGinniss complains were nothing more than 'tawdry gossip' that amounted to the wishful fantasies of disturbed individuals," Tiemessen's letter said.
Tiemessen, reached at his Fairbanks, Alaska, office, declined to discuss the subject further. McGinniss could not immediately be reached for comment.
Palin's husband, Todd, issued a statement about McGinniss and his book before it was released, saying the author had a "creepy obsession with my wife."
Among the more sensational allegations contained in the book is an account of a one-night stand Palin is purported to have had as a 23-year-old unmarried sports reporter with a future professional basketball player.
But most of the book is devoted to Palin's actions as mayor of Wasilla and governor of Alaska, up to her abrupt resignation from that post in July 2009.
The book portrays Palin as fascinated with celebrity and self-advancement but disinterested in governing.