The childhood secrets of boy wizard Harry Potter, before he went to Hogwarts, will be revealed in a charity auction next month.

According to Reuters, author JK Rowling has penned an 800-word outline of a prequel to the seven book series which will be sold at an auction on 10 June by Waterstones.

The outline, which ends with the line "From the prequel I am not working on - but that was fun!" is one of 13 story outlines written for the auction by famed authors including new Bond writer Sebastian Faulks.

Waterstone's CEO Gerry Johnson said: "What's Your Story? just gets more and more exciting, all these brilliant works by amazing writers and illustrators, every one a small masterpiece."

He added: "We never dreamed that JK Rowling would donate something so precious and we're incredibly grateful."

Other authors who have donated outline works are Nick Hornby, Tom Stoppard and Irvine Welsh.