NEW YORK -- Oprah Winfrey once boasted that it was a book that kept her up at night. Now, the talk show queen might be having some restless nights because of an allegation against the author of the book, "A Million Little Pieces."

James Frey's best-selling memoir about substance abuse has come under intense scrutiny for alleged fabrications.

Frey's book has sold millions of copies, but an investigative Web site has alleged substantial inaccuracies, with inflated claims about his criminal record and about his involvement in an accident that killed two high school students.

An article that appeared on TheSmokingGun.com revealed that police reports, court records, interviews with law enforcement personnel, and other sources have put the lie to many key sections of Frey's book, which details his battle with substance abuse. The site claims Frey's memoir makes wild exaggerations about his past.

Frey's memoir was published in 2003 and became a sensation last fall after Oprah Winfrey picked it for her book club. He has defended his work, writing on his Web site last weekend that "I stand by my book, and my life."

Doubleday has issued a statement of support, saying that memoirs are "highly personal."

But the Smoking Gun site said Frey admitted that "he had embellished central details of his criminal career" in the book, which was supposed to be a non-fictional work.

The Web site said that in an Oct. 26 'Oprah' show entitled "The Man Who Kept Oprah Awake At Night," Winfrey hailed the book as "like nothing you've ever read before.

Frey will appear Wednesday night on CNN's "Larry King Live." Bridget Leininger of CNN said Tuesday that Frey would not be interviewed for the entire hour-long program, but offered no other details.