A series of children’s Spy books is being pulled from the shelves after they inadvertently contained a link to pornography.

Publishers of the the popular books by Andrew Cope, Puffin, has paused sales and distribution of the books and is working with schools, libraries, and retailers to remove copies from circulation.

A web address printed in some editions of the popular Spy Dog, Spy Cats and Spy Pups books led to bonus features but now displays inappropriate pornographic content.

A spokesperson for Libraries Unlimited which run Devon library services said: “A message was sent out to all libraries to check the books. All those that have the website in them (not all have the website in it), the website has been covered over.

“The stock team have reserved all items that are currently on loan, so that they can be inspected upon return, and have deleted all items that are missing or not been seen for a long time.

“This will prevent them being self-issued, if they turn up, forcing the borrower to take it to a member of staff, who can then inspect the book.”

In a joint statement, Andrew Cope and Puffin Books, said: "In some editions of the Spy Dog, Spy Cat and Spy Pups series there is a reference to the author, Andrew Cope’s former website for the series which was owned and managed by him.

"We understand an unconnected third party has very recently taken control of the domain name and is using it to display a different website with inappropriate adult content.

“This website is not associated with Puffin or Andrew Cope. We are asking people not to visit the website and ensure that children do not visit it either.

“We are taking this extremely seriously and are acting on this issue as a matter of urgency through the appropriate channels to get this website removed.”