The "graphic and harrowing memoir" is written by an anonymous author, sparking controversy over fears the claims could have been made up.
But the book's American editor Lorin Stein insists the story is true, saying: "We believe in the authenticity of this book."
According to The Independent, the publishers have gone so far as to take the unusual step of attaching a pre-emptive note to the text in order to verify its authenticity.
"I have no doubt about her honesty or clarity of mind," Stein writes.
"We are publishing it because we believe it is a work of art."
Stein also insists they went to great lengths to verify the story, saying they "interviewed old friends to whom the author confided the fact of her abuse years ago," and they have also seen medical records, which were unavailable to the author when she was writing, that match her recollections.
The book's pages are filled with disturbing and graphic descriptions of "almost unbearable intensity" according to the publisher - so much so that some are questioning whether the book is "art or exploitation".
The writer, believed to now be in her forties, reveals her dad first abused her when she was three years old - with the sexual relationship stretching into her twenties.
The memoir includes shocking details, including how she apparently came to enjoy much of the sex with her father - particularly during her teenage years.
She also claims her mother - who went on to split with her dad when she was ten years old - and other family members were aware of the abuse.
The author writes: "To my mother, I was the other woman. She often told me that she wished I hadn't been born."
When she was eight, the family moved to a new house.
The book reads: "I assumed the master bedroom was for me and my father and that my mother would sleep in one of the other bedrooms."
Several British publishers are understood to have snubbed the chance to bid for the UK rights to the book, with one reportedly branding it "off-putting and uncommercial".
Early online reviews of the book have been mixed.
"It's like Lolita, sans the wit and poetry of Nabokov," wrote one person on goodreads.com.
"The writing is beautifully done with the author mastering her descriptions of sights, smells, and sensations effectively enough to leave a print on the mind. Unfortunately, this is a true story and the anonymous author doesn't hold back on the sometimes horrifying details. Well worth reading if you've got the stomach."
Some were not so positive:
"The writing was all over the place and it ended weird. There wasn't really a solid beginning or conclusion it was just a compilation of the author's memories. The memories were all over the place and there wasn't really a solid time line or story. I can't believe that this is true."
Despite the criticism, Alexis Kirschbaum at Bloomsbury stands by her decision to publish the book:
"The Incest Diary is the most disturbing book I have ever read, and it is not only because of the nature of the abuse the author recounts. It is because the author's account is a chronicle of pleasure. I am very uncomfortable with that. I know now that it is a symptom of her abuse, and it is perhaps the most unbearable symptom there is, to find pleasure in what essential destroys you.
"I decided to publish the book because, after almost two decades in publishing, I know how rare it is to discover a book that troubles you into having dozens and dozens of conversations, some of the most interesting I have had in my life. I couldn't stop thinking about it, and I couldn't stop talking about it. I still can't. And I won't be the only one.
"Sparse, poetic, violent, totally without precedent in the way she tells her story, we have discovered not just a courageous writer, but a gifted one, and her account left me in awe.
"The Incest Diary raises complex issues about art, freedom, consent, and I believe the author's experience must be heard for this reason. It matters that the world knows this has taken place. It matters that it is told in this way, with such beauty. I have endeavoured to publish the book with the care, discretion and dignity it deserves.
"I believe the book will make many people uncomfortable and indignant; many people will say it shouldn't have been published; but it will make others feel awakened, witnessed, less alone. "Those are the people I most care about, and why I think publishing this book is so important".
WHERE TO GET HELP:
If you are worried about your or someone else's mental health, the best place to get help is your GP or local mental health provider. However, if you or someone else is in danger or endangering others, call 111.
If you need to talk to someone, the following free helplines operate 24/7:
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There are lots of places to get support.
For others, visit: https://www.mentalhealth.org.nz/get-help/in-crisis/helplines/
- news.com.au