It was claimed that someone had hacked into JK's website and discovered that the next book was going to be called Harry Potter and the Pillar of Storgé.

Potter fans looked into it and reckoned it was a very clever trick.

JK's spokesman dismissed the gossip, exclusively telling CBBC Newsround that it was "definitely a hoax".

We've also found out that JK is expected to update her site really soon.

The rumour started when a Potter fan claimed to have got through a door on the site that is normally tightly closed.

Convincing

They said that behind that door was a message from JK herself dated 1 July that revealed the title.

There was even a video clip that looked just like the other bits of the site, which at first convinced some people.

But some of the things in that video clip didn't look right to Potter fans.