Author JK Rowling's seventh and the last Harry Potter book is titled Harry Potter and the Deathly Hallows.

The name of the book was unveiled on Rowling's official website in the form of a puzzle whereby the author invited fans to find a key to a locked door. The book will conclude the author's massively popular series featuring the young wizard.

Rowling admits she has not yet finished writing the book.

"I am now writing scenes that have been planned, in some cases, for a dozen years or even more," Rowling revealed in her website, adding: "I don't think anyone who has not been in a similar situation can possibly know how this feels. I am alternately elated and overwrought. I both want and don't want to finish this book."

The author gave no new clues about what will happen in the book, which is expected to be published next year. She had earlier stated that 2 of her characters will die, and hinted that Harry might not survive.

The first six books in the Potter series have sold more than 300 million copies worldwide and been translated into 63 languages, making Rowling Britain's highest-earning woman. The first four novels have been turned into films, while the fifth, Harry Potter and the Order of the Phoenix, is currently in production and is due for release in July 2007.