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.
“This is an in-depth and complex legal process and will take time.
“In addition, we have immediately paused on the sale and distribution of the books whilst we deal with this matter.
“We are currently working with retail and education and library partners to remove the books from shelves for the time being.
“We are asking anyone who has copies of these titles to temporarily remove these books from their shelves.”