The sixth instalment of JK Rowling’s blockbuster series, Harry Potter and the Half-Blood Prince, has sparked a supermarket price war.

Tesco, Asda and Sainsbury all said they would be slashing the price from its recommended retail price of £16.99.

But they were all beaten by Kwik Save, which is selling the book for £4.99.

For more details, see The Grocer tomorrow.