When the final Harry Potter book goes on sale in India and China on Saturday morning, the maturing boy wizard's publishers will need their own magic to stave off attacks from pirates.

India's and China's vast populations mean they are alluring publishing markets. Printers have produced more than 8m legitimate Harry Potter books in China alone, while in India fans of the series have already placed advance orders for 240,000 copies of Harry Potter and the Deathly Hallows, according to Penguin India.