London: Sales of a book, which was secretly written by ` Harry Potter` author JK Rowling, increased by a whopping 500,000 per cent on Sunday night, after she was unmasked as its writer.
The `Cuckoo`s Calling` had been written under the pseudonym Robert Galbraith, who readers were duped into believing was a retired military policeman and father-of-two, the Daily Express reported.
Rowling, who plans to write a series of the crime novel, was finally outed at the weekend after suspicions began to emerge following rave reviews after it was published in April.
The novel had jumped to number one on Amazon`s bestsellers listing from 4,709.
The book was described as a "stellar debut" by one critic, while another said that it was "a mature, realistic take on an often-done genre."