NEW YORK -- Harry Potter author JK Rowling is asking people who have inside information on her character's final adventure to be silent.

Rowling said on her Web site that there are rumblings about spoilers being made public.

The seventh and final Harry Potter book is eagerly anticipated by the millions of fans around the world. Rowling has said two major characters will die in "Harry Potter and the Deathly Hallows," which comes out July 21.

Even a fan site that's reported getting spoiler warnings about what's in store is pleading for secrecy.

At the Leaky Cauldron site, Webmaster Melissa Anelli wrote that fans have waited 10 years for the final revelations, and they don't want the last surprises ruined.

Rowling said that she was grateful for the precautions that Anelli and the site are taking.

"I add my own plea to Melissa's for one reason, and one only: I want the readers who have, in many instances, grown up with Harry, to embark on the last adventure they will share with him without knowing where they are they going," Rowling wrote.

More than 300 million copies have sold of the previous Potter books. "Deathly Hallows" has more than 1 million pre-orders on Amazon.com alone.

Rowling insisted that she wasn't trying to put the spoilers to a stop for the sake of preserving sales.

"Some, perhaps, will read this and take the view that all publicity is good publicity, that spoilers are part of hype, and that I am trying to protect sales rather than my readership," Rowling wrote. "However, spoilers won't stop people buying the book, they never have -- all it will do is diminish their pleasure in the book."

The release of "Deathly Hallows" will come just more than a week after the July 13 release of the fifth Potter film, "Harry Potter and the Order of the Phoenix," starring Daniel Radcliffe as Harry, Emma Watson as Hermoine and Rupert Grint as Ron.

Potter studio Warner Bros. recently announced that the three core cast members have signed on for the two remaining films in the series.