A Harvard University student whose first novel made her one of the youngest authors signed in decades has admitted that she borrowed material from another author.

Kaavya Viswanathan, 19, says she accidentally used sections from the work of Megan McCafferty, and has promised to amend future editions of her book which is currently on The New York Times bestseller list.

The book, How Opal Mehta Got Kissed, Got Wild, and Got a Life was published in both the US and UK in March by Little Brown and Company – the first in a two-book deal which was reportedly worth six figures and which the teenager signed when she was just 17. The DreamWorks studio has already acquired the film rights.

The 320-page novel tells the story of Opal, a hard-driving young woman who gains straight A's in high school but gets rejected from Harvard because she forgot to have a social life. Her father concocts a plan which he codenames HOWGAL (How Opal Will Get A Life) to get her past the admission’s office.

On Sunday, however, the Harvard Crimson cited several passages which closely resemble the style and language of Megan McCafferty’s novel published in 2001.

Kaavya Viswanathan responded to the claims in a statement issued by her publisher:

"When I was in high school, I read and loved two wonderful novels by Megan McCafferty, Sloppy Firsts and Second Helpings which spoke to me in a way few other books did. Recently, I was very surprised and upset to learn that there are similarities between some passages in my novel …and passages in these books.

"While the central stories of my book and hers are completely different, I wasn’t aware of how much I may have internalised Ms McCafferty’s words. I am a huge fan and can honestly say that any phrasing similarities between her works and mine were completely unintentional and unconscious. My publisher and I plan to revise my novel for future printings to eliminate any inappropriate similarities.

"I sincerely apologise to Megan McCafferty and to any who feel they have been misled by these unintentional errors on my part."

Michael Pietsch, the Little Brown publisher, said that he did not think the borrowed material was caused by the pressure of being a student and an author.

"Every word in that book was written by her, for better or for worse," he said, adding that work on a new edition would begin "tomorrow". The book had an initial print run of 100,000 copies.

McCafferty’s books, published by Random House, follow Jessica, a New Jersey girl who excels in high school but struggles with her identity and longs for a boyfriend.

McCafferty is a former editor at Cosmopolitan who has written three novels. Some readers had pointed out the likenesses, she said.

"After reading the book in question, and finding passages, characters, and plot points in common, I hope this can be resolved in a manner that is fair to all of the parties involved," she said.

Stuart Applebaum, a spokesman for Random House said that lawyers are examining the books for similarities. He would not comment on the extent of those similarities or what action the company might take.

"I’m sure everyone will take these concerns very seriously," he said. "And more to come."

Viswanathan has said in earlier interviews that the heroine in her book bears similarities to herself. Opal and Kaavya both have Indian heritage, a New Jersey upbringing, and attend Harvard.

There is also a teenage boy in the book who has a striking resemblance to a classmate for whom she had an unrequited crush. But the author said last month that these were just superficial details and the book is invented fiction.

Kaavya Viswanathan was born in Madras, India, and her family moved to Scotland when she was 3. They moved again to New Jersey when she was 12. She has said her biggest goal is to win a Man Booker award.

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