JK Rowling has leapt to the defence of a new ebook about Harry Potter's exploits after fans complained they were paying for content that was free on the website.

Fans have complained that the Pottermore Presents series of online escapes which sell for £1.99 each contain very little original content from the Edinburgh-based writer.

The e-books were published yesterday consisting of three books that formed part of a package of themed writing from the Pottermore website.

Glasgow Times:

There are chapters on items well known to Potter afficianados in the 10,000 word books, plus maps and entries on all of the Ministers for Magic - the wizarding answer to the Prime Minister.

But the website had promised previously “original, never-seen-before” writing from Rowling would comprise certain chapters.

Most of the chapters relates to Professor McGonagall of Hogwarts fame, which are available on the website. It appears there is just a few hundred words of material from the author.

Edinburgh-based Rowling's name is mentioned on the front of the books, but the writing has been compiled by website staff.

One fan wrote on Twitter: "I'm grateful for her writing Harry Potter but more representation would've been great."

Another, Ana de Carvalho, added on the micro-blogging site: "Some people think they know the Harry Potter characters more than the creator of them."

American fan Sarah Spivet tweeted: "Is it me, or is there not that much new info in the HP [Harry Potter] shorts that isn't already on Pottermore for free?

Anotther fan, writing from Brisbane, commented that they were making information available that was already on the site and questioned whether it was a money making exercise.

Rowling responded on Twitter to the comments by saying: "We had many, many requests to make the extra writing available in this format."

Pottermore's director of product creative and content Anne Rafferty wrote on the website: “We read through everything in our archives, took pieces written by Rowling and the Pottermore editorial team, and sewed it all together.”

The new books include Hogwarts: An Incomplete and Unreliable Guide, Short Stories from Hogwarts of Power, Politics and Pesky Poltergeists, and Short Stories from Hogwarts of Heroism, Hardship and Dangerous Hobbies.