Harry Potter fans can finally find out their hero's fate, after the seventh and final book in the series went on sale across the world.

The first copies were snapped up just after midnight, as author JK Rowling read excerpts to 500 devotees at London's Natural History Museum.

She had admitted to 'excitement, nerves and relief' as the launch approached.

'All the secrets I have been carrying around for so long will be yours, too,' she wrote to fans on her website.

'Within hours you will know what happens to Harry, Ron, Hermione and the rest in their final adventure.

'Those who guessed correctly will be vindicated, and those who guessed wrongly will not, I hope, be too disappointed!'