"After looking closely at all the information that we've gathered, we have decided to further extend the Beta period so we can improve Pottermore before giving more people access," said an announcement on the Pottermore blog. "This means the site will not be opening to new users in the immediate future, but please know that we will open registration as soon as we can."

Last month, Charlie Redmayne, formerly chief digital officer at HarperCollins, announced he was leaving the book publisher to become CEO of Pottermore.