JK Rowling has urged fans not to try to predict the plot of the new Harry Potter novel.

The final instalment in the series, Harry Potter and the Deathly Hallows, will be published on July 21, but fans are becoming impatient.

However, the novel's author posted on her official website to urge fans not to spoil the surprise by seeking out spoilers on the internet.

She wrote: “We're a little under three months away, now, and the first distant rumblings of the weirdness that usually precedes a Harry Potter publication can be heard on the horizon.

"I want the readers who have, in many instances, grown up with Harry, to embark on the last adventure with him without knowing where they are going.

“Spoilers won’t stop people buying the book - they never have. All it will do is diminish their pleasure in the book.”