Two Harry Potter books signed by JK Rowling and left on a shelf for years are set to go up for auction and are expected to be sold four thousands of pounds.

The author paid a visit to a Waterstones in 1999, where she met pupils from Millfield Preparatory School in Glastonbury, Somerset.

Rowling signed copies of the first two books in the best-selling series, Harry Potter and the Philosopher's Stone and Harry Potter and the Chamber of Secrets.

School librarian Janette Tuckwell left with signed copies of both, but didn't realise their worth and left them on a dusty shelf for two decades.

Now she's putting the novels up for auction, where they're expected to fetch up to £2,000 each.

The Herald: A copy of Harry Potter and the Chamber of Secrets signed by JK RowlingA copy of Harry Potter and the Chamber of Secrets signed by JK Rowling (Image: Hansons)

She said: “They told me they had a children’s author coming to the shop and would I Iike to arrange for pupils to come along.

“I said yes and, together with an English teacher, took a Year 6 class of 10 and 11 years old to the store.

“The children’s author turned out to be JK Rowling, author of the Harry Potter books.

“At that time, her books were popular but the Potter phenomenon hadn't gone global.

“She was brilliant with the pupils. I remember being very impressed by her dedication and the way she handled the children’s questions.

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“If they asked something about the books she would refer to a character or plot line to make sure they had read it.

“She was very thorough and professional.

“I took a photo of her with the pupils and she signed two books for me.

“They have been gathering dust on a book shelf for more than 20 years but, after reading an article about how sought after Potter books are, I decided to contact Hansons Auctioneers.

"The Potter books were a godsend to libraries.

“They got so many kids into reading They had to keep up as they liked to discuss the plot with their friends.

“I read the first couple of Potter books and enjoyed them. Everyone was reading them.”

The books will go up for auction on March 7, with the Chamber of Secrets a signed first edition copy.

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Hansons’ books expert Jim Spencer said: "In a market completely flooded with fake Rowling signatures, it's lovely to have such great provenance with these signed books.

“It's nice to think of those excited children going to meet JK Rowling in 1999.

“It highlights just what makes Harry Potter so special - not many books get children queuing up to meet the author.

“The original photograph is proof of the event, which means collectors around the world can bid with confidence, but it's also a heart-warming memento of a reading craze - before any of the films had been made.”