Image caption Digital book sales in the UK shot up from £4m to £16m in 2010

US writer John Locke has become the first self-published author to sell more than one million e-books in the Kindle Store on Amazon.

Locke, from Kentucky, used Amazon's Kindle Direct Publishing to publish and sell his nine novels.

The author has become the eighth author to sell over one million Kindle books and joins the likes of Stieg Larsson and James Patterson.

The Kindle is an e-book reader which enables consumers to download novels.

"It's so exciting that self-publishing has allowed John Locke to achieve a milestone like this," said Russ Grandinetti, vice president of Kindle content.

Locke's latest book is called How I sold 1 Million e-books in 5 Months.

His other books include Saving Rachel, Don't Poke The Bear!, and Vegas Moon.

Other authors in the so-called Kindle million club alongside Larsson, Patterson and Locke are Nora Roberts, True Blood creator Charlaine Harris, Lee Child, Suzanne Collins and Michael Connelly.