AUTHOR JK Rowling has revealed she chose the pseudonym for her crime novel as a tribute to a famous American politician and a name she loved as a child.

Rowling, who wrote The Cuckoo's Calling under the name Robert Galbraith, revealed more details about the secret project which was only unmasked last week, several months after the book was published.

The Edinburgh-based author said she had adopted the name Robert as it was her favourite male name and also in honour of Robert Kennedy, the American politician who was assassinated back in 1968.

Galbraith was chosen as the surname as when she was a child, Rowling said she liked the made-up name of Ella Galbraith. She had considered publishing the book under the pseudonym LA Galbraith but thought it best to avoid two initials in the secret name.

Since it was revealed Rowling was the real author of the crime novel sales have rocketed and the publishers have printed an extra 140,000 copies.

But on the website dedicated to the author "Robert Galbraith" she denied releasing the book under a false name was all part of a clever marketing ploy.

She insisted it would have sold many more if it had been released under her own name.

Under a section which was entitled "frequently asked questions" she also said her home city of Edinburgh was a great place to locate a book.

However, she chose London as the Scottish capital already had plenty of books set there.

And, revealing there will be a sequel to The Cuckoo's Calling, she said there were some signed copies of the first Robert Galbraith book.

She said she had spent a weekend practising the signature.