Rowling corrects Potter error

Author JK Rowling has been forced to correct a mistake in her Harry Potter and the Half Blood Prince book, after fans noticed an inconsistency.

In the previous Potter book, Harry Potter in the Order of the Phoenix, Rowling writes that character Hermione Granger takes 10 exams.

However, in the hardback edition of follow-up Harry Potter And The Half-Blood Prince Rowling states that Granger took 11 exams.

Publisher Bloomsbury has now corrected the paperback edition so it reads that she took 10 exams.

A Bloomsbury spokesman says: "We can confirm that there was an error."