A copy of J.K. Rowling's handwritten collection of fairy stories, The Tales of Beedle the Bard, has sold at Sotheby's for £1,950,000.

One of only seven copies in existence was sold in aid of The Children's Voice, the charity co-founded by Rowling to campaign for children's rights.

It had only been expected to raise about £30,000 and Rowling was delighted with the final sum. "This will mean so much to children in desperate need of help," she said in a statement. "It means Christmas has come early to me."