JK Rowling reveals she wrote the crime novel "The Cuckoo's Calling" under the pseudonym 'Robert Galbraith'.

JK Rowling rose to fame with her "Harry Potter" series and the fan following she earned has been loyal to her ever since. The evidence of their loyalty was witnessed when the author revealed she had penned the crime novel "The Cuckoo's Calling" under the pseudonym 'Robert Galbraith'. Within hours of the revelation, the book topped many charts and jumped more than 5,000 places on Amazon. The digital version of the book stands at number one in the iTunes book chart.

A spokesman for bookseller Waterstones said: "This is the best act of literary deception since Stephen King was outed as Richard Bachman back in the 1980s."

Nielsen BookScan reported that the book had sold fewer than 500 copies since its publication in April, 2013 until Rowling revealed it was her book in the Sunday Times. The book was published by Sphere, part of Little, Brown Book Group which published Rowling's first novel for adults, "The Casual Vacancy."

The Bookseller reports that Little, Brown's spokesperson has confirmed that the publishers have ordered an "immediate reprint."

Many publishers were left red-faced for having rejected the book and one of them was Kate Mills, publishing director of Orion.

"When the book came in, I thought it was perfectly good - it was certainly well written - but it didn't stand out," Mills said. "Strange as it might seem, that's not quite enough. Editors have to fall in love with debuts. It's very hard to launch new authors and crime is a very crowded market."

On the social reading website Goodreads, the novel has a rating of 4 out of 5, indicating almost completely favorable reviews for the book from a total of 82 votes and 36 reviews. The readers on the website call it "a mature, realistic take on an often-done genre" with "some of the most endearingly likeable characters in the genre."