Four months ago the TV host announced her latest book club selection - the memoir A Million Little Pieces by former drug addict, criminal and alcoholic, James Frey. An emotional and at times teary Oprah sang the book's praises last October, saying Frey's memoir of his bad-boy youth was "like nothing you've ever read before" and "raw and so real".

I've discussed in the past the power of an Oprah stamp of approval. So it's no surprise that after pointing her book club devotees in the direction of Frey's book, it went on to become the highest-selling non-fiction book in the US last year. There's even talk of a movie version of A Million Little Pieces starring Brad Pitt.

There's just one little problem. This month Frey was branded a liar. According to TheSmokingGun, an American investigative website which ran a six-week investigation, the author fabricated much of his story. That would be okay, except that A Million Little Pieces was being touted by Frey and his publishers as a "fiercely honest" memoir. Now Frey's being called "the man who conned Oprah".

Debate has since raged over whether publishers (and Oprah) need to ensure the accuracy of "memoirs" or whether, as Frey said in his defence, memoirs are by nature imperfect. Frey has gone on record as saying: "I don't think it should be held up and scrutinised the way a perfect non-fiction documentary would be, or a newspaper article." Maybe he's right. Even Queensland Premier Beattie had a couple of former school friends question the accuracy of his high school recollections in his autobiography, Making a Difference.

Memory is a highly subjective thing. Yet there's a huge difference between discrepancies in the recounting of a real event and fabricating an event altogether. The most obvious question is why not just call the bloody thing "a novel"? That's a question I'm sure Norma Khouri is still asking herself after the brouhaha which erupted in 2002 over Forbidden Love, her faux-memoir of the honour killing of her best friend, Dalia. The simple answer is that books of non-fiction outsell fiction.

Back to Frey. The author has now admitted that certain parts of the book were "embellished" although TheSmokingGun website seems to have clear evidence that Frey has out-and-out lied.

But forget him. Where does this leave Oprah? She has publicly called the controversy "much ado about nothing" and insisted that the book still resonates with her. Now she's receiving more criticism for not having publicly wiped her hands of the author. I'm not sure what that would achieve - apart from giving Frey more column centimetres. What's important is that readers know what they're literally buying into when they purchase A Million Little Pieces - not a memoir but a novel inspired by a true story.

This isn't the first time Oprah has had trouble with one of her featured authors. Back in 2001 she waved her book club wand over The Corrections by Jonathan Franzen, calling it "richly realistic, darkly hilarious and deeply humane" and heralding it as a must-read. While Franzen's novel was undoubtedly a bestseller before Winfrey came along, Franzen's publishers Farrar, Straus & Giroux reportedly bumped up the book's initial 90,000 print run with an additional 680,000 copies after the Oprah announcement.

Yet in a bewildering move, while Oprah was heaping praise on the novel and hoping to demonstrate to publishers again that there is a bigger market for "literary" books than they think, Franzen was dropping anti-Oprah remarks to the press, implying that he felt a stigma by being associated with her book club and disliked the idea of having a corporate affirmation - such as the Oprah Book Club - on his book.