A spokeswoman for Potter's British publisher Bloomsbury said earlier this week: "There is a lot of fan fiction and a lot of dreamers on the Internet, and people are very clever about what they put together ... We are amazed people want to spoil it."
In the United States, media has reported photographs circulating on the Internet of every page of "Deathly Hallows", although publishers declined to say whether any were genuine.
This week Scholastic initiated court action against one Web site,
www.gaiaonline.com, to persuade it to take down Harry Potter material it had posted, the Los Angeles Times reported.
Potter fans reacted angrily to recent leaks.
"I hate it when people ruin things like this for everyone else who wants to enjoy it the right way," one contributor wrote on the Mugglenet site. "I think that's just the most awful thing ever. Especially when there's spoilers where you least suspect it. People are jerks."