The Nine Inch Nails frontman, who picked up an Oscar last month for his Social Network score, had previously been in talks to compose the music and make a cameo appearance in the historical action film.
However, Reznor ruled out his involvement in Vampire Hunter in an update on the Nine Inch Nails forum.
"Don't believe everything you read. As it turns out, I WON'T be working on (acting or scoring) ALVH after all (sic)," he wrote.
"There's no juicy story here, it's just that when the news mysteriously leaked out about my involvement I hadn't made up my mind completely, because various aspects of the project were changing.
"I felt the need to say something earlier this week because my inbox was filling up with speculation, and at that moment I thought I would be doing it. Confused yet? Apparently I am. Bottom line, I wish them the best with the film and I'm sure it will still be great."
Reznor added that he is still "fully engaged" in writing the HBO/BBC Worldwide sci-fi miniseries Year Zero, which is based on Nine Inch Nails' fifth studio LP of the same name.