Original sketches for the Harry Potter books are to be displayed and put up for sale at the Glasgow Art Fair.

The early drafts by artist Cliff Wright are expected to fetch five-figure sums when they go under the hammer in the next week. Mr Wright illustrated the book Harry Potter and the Prisoner of Azkaban.

The pen and pencil drawings are the instantly recognisable forerunners of the images which appeared on the front and back covers of the second novel of JK Rowling's series.

The front illustration, which features the bespectacled wizard and his classmate Hermione Granger clinging to the back of hippogriff (pictured), is expected to sell for about £13,000.

The second sketch, which features a snarling dog, is predicted to raise £11,000.

The images are in mint condition. They were drawn in 1998.

Mr Wright said: "The images are part of a series of ten which were sent to the publisher Bloomsbury as rough ideas for character development and composition.

"Each drawing was submitted by fax and returned with comments. The designs were also passed on to JK Rowling for her approval and any comments passed back to me."

Micky Middleton of art firm Red Gallery, who is handling the sale, predicted the illustrations would attract a huge amount of interest.

He said: "I would encourage collectors to come and see these original works in situ at the fair."

The art fair will run from Thursday through the weekend at George Square.