Potter Raising Money For Charity

Rowling has produced Fantastic Beasts and Where to Find Them, which is the book junior wizard Harry bought to prepare him for Hogwarts school.

She has also written Quidditch Through The Ages, a library book that Harry uses to learn the rules of the school's signature sporting activity, which involves teams playing ball on broomsticks.

"When Comic Relief asked me to write something I thought I would just love to write the two books," Ms Rowling told the BBC.

"I did two because I had two in my head and I couldn't really decide between Quidditch and Fantastic Beasts, so I decided to do them both."

The Edinburgh-based single mother - whose first name is Joanne - has sold more than 30 million copies of her schoolboy wizard books worldwide.

Comic Relief founder Richard Curtis approached Rowling to write a story saying he was sure she would not be able to but he would still love her books regardless.

"It was a very clever way of asking somebody to do something, though I didn't really need much persuading" Rowling told the BBC.