JK Rowling says that her books, which recount the adventures of a young orphaned wizard, were "very moral" in their representation of the struggle between good and evil.

"I wasn't going to pretend that an evil presence is a cardboard cut-out and nobody gets hurt.

"If you're writing about evil you genuinely have a responsibility to show what that means and that's why I'm writing them the way I'm writing them," she said.

Harry Potter, the bullied orphan who becomes a heroic young wizard, is causing controversy

The books have been criticised by parents in South Carolina who called on school authorities to keep the three Harry Potter novels out of the classroom. The parents had been unhappy at the way the book depicted death, evil and hatred.

But the author rejected such claims, saying that the novels needed to include such ingredients to honestly tell their stories.

"There are those things in the book because I made a very conscious decision right at the beginning that I was writing about someone evil and I was not going to tell a lie," said JK Rowling.

"I think they're very moral books. I see children as innately good unless they've been very damaged. That's where I'm coming from."

Support for the novelist has also come in the form of an online poll in a newspaper in Atlanta, Georgia, which found overwhelming backing for the stories not to be banned from schools.

The Atlanta Journal-Constitution poll found 93% of respondents were against a ban.