Rowling's crime novel 'The Cuckoo's Calling' had TV offers before she was exposed

J.K. Rowling has said that 'The Cuckoo's Calling' had respectable sales and two TV adaptation offers before it was revealed that she had authored the mystery novel under pseudonym Robert Galbraith.

Writing on Galbraith's author website, the 'Harry Potter' author said that her crime-writing alter ego was doing rather better than they had expected him to, Stuff.co.nz reported.

She wrote that Galbraith had sold 8,500 English-language copies across all formats at the point when Rowling was outed.

The book, which was published in April, has topped best-seller lists since Rowling's was unmasked.

She wrote that though she is grateful for all the feedback from publishers and readers, being Robert Galbraith has been all about the work and she hoped to keep the secret as long as possible.

Rowling- who said she had taken the name from her political hero, Robert Kennedy, and a name she'd invented in childhood, Ella Galbraith- also confirmed that she had signed a few copies of the book under her pen name, after working on a fake autograph.

She said that she has finished a second Robert Galbraith book featuring detective hero Cormoran Strike, to be published next year.