By Caroline Briggs
BBC News entertainment reporter
Fans of Harry Potter are being urged to watch out for internet scams after a website claiming to offer copies of the Half-Blood Prince was closed down.
The website claimed to have all the Harry Potter titles available
JK Rowling announced last month that the sixth Harry Potter book in the series would be released in July.
But a website claiming to sell electronic versions of the finished book appeared last week.
The website was closed on Monday afternoon after the BBC News website alerted Rowling's literary agent.
It purported to offer an electronic version of Harry Potter and the Half-Blood Prince for $9.95 (£5.30) - six months before the eagerly-awaited book is due to be published on 16 July.
It promised fans: "This book is available now in electronic variant only. If you do not wish to wait for six months more, buy and start reading right now! Be the first to reveal all the secrets!"
It also claimed to have JK Rowling's other Harry Potter titles for $6.95 (£3.70) with a "special offer" on all six titles for $29.95 (£16).
But Christopher Little, Rowling's literary agent, told the BBC News website that none of her Harry Potter titles were available in electronic form.
He said: "The internet is monitored all the time for things like this and usually we manage to get them taken down more quickly than this one.
"Similar things happened in the run-up to the publication of the fifth Harry Potter book.
"Unfortunately Harry Potter fans have found out that there are large number of people out there who want to cash in on this wonderful phenomenon and it is very sad.
"I hope that all genuine fans will keep a wary eye out for this kind of thing."
Harry Potter fansite, The Leaky Cauldron, was alerted to the scam by emails from angry fans of the teenage wizard.
Managing editor Melissa Anelli told the BBC News website she and another colleague had tried entering their valid credit card details to see if it was making illegal e-books available, using a fan fiction, or fishing for credit card numbers.
What is Fan Fiction?
Fan fiction is a story based on the world of Harry Potter, which is written by a fan and published on the net
A number of websites carry thousands of stories inspired by the teenage wizard
Earlier this year JK Rowling gave her blessing to fan fiction
Writers are asked to ensure the stories are not obscene and are not credited to JK Rowling
TV programmes such as Doctor Who and Star Trek are other popular sources of fan fiction
She said: "The site declined my card, which, because of my credit level, was impossible.
"I thought I'd get a fan fiction sent back, but instead I was told my credit card details had been declined."
Ms Anelli said it was the first scam they had been alerted to by fans.
"When we were waiting for Order of the Phoenix to be released, my email inbox was filled with things like this, but this is the first one for Half-Blood.
"Harry Potter fans are so angry about it. Everyone wants to protect JK Rowling and no-one wants to know anything about the book until it is ready."
Harry Potter and the Half-Blood Prince topped Amazon's book chart less than 24 hours after its release date was announced on 21 December.
It will be published simultaneously in the UK, the US, Canada, Australia, New Zealand and South Africa.
Thousands of customers desperate to get their hands on the wizard's latest adventure have placed pre-orders for the book.