Many of King's novels have been successfully adapted for screen

The Australian Broadcasting Corporation said staff at the Alice Springs book store did not initially realise the writer was autographing his own novels.

Bookshop manager Bev Ellis said: "When you see someone writing in one of your books you get a bit toey [nervous].

"We immediately ran to the books and lo and behold, there was the signature."

Ms Ellis later approached the author at a nearby supermarket and said he was "very nice, charming".

"Well, if we knew you were coming we would have baked you a cake," she told the writer.

'Embarrassing'

The prolific author, best known for works such as Carrie, The Shining and Misery, signed six books including his most recent novel, Lisey's Story.

Most of the books will be given to local charities, though one was purchased by a customer who was in the store with King.

Ms Ellis added that it was common for authors to visit the shop, check if their books are on the shelves and sign some copies.

"If they're not on the shelves, they'll ask about them. It's embarrassing if we haven't got their work," she said.

King's representative in Australia told the media he was unaware the author was in the country.