Media playback is unsupported on your device Media caption JK Rowling: "There were a couple of the Potters and I definitely knew that they needed another year"

Author JK Rowling says she is tempted to create a "director's cut" of two Harry Potter novels, because she ran out of time to finesse them.

Rowling, whose first adult novel, The Casual Vacancy, is published on Thursday, said she had deliberately taken her time to write it.

"There were a couple of the Potters and I definitely knew that they needed another year," she said.

Her final Potter book, Harry Potter and the Deathly Hallows, came out in 2007.

"I had to write on the run and there were times when it was really tough," she told BBC arts editor Will Gompertz.

"And I read them, and I think 'Oh God, maybe I'll go back and do a director's cut', I don't know.

"But you know what, I'm proud I was writing under the conditions under which I was writing, no one will ever know how tough it was at times."

Emma Watson, who starred as Hermione Granger in the Harry Potter films, said the author was "too hard on herself".

"I think they [the books] are the way they were meant to be," she told BBC Newsbeat.

'Not for children'

Rowling said she wrote her latest novel simply because she "wanted to". It is aimed specifically at an older audience and includes adult themes and swear words.

"I hope that we've made it really clear that this isn't a book for children," she said.

Image caption Rowling says The Casual Vacancy is about "slicing through a society with everything that that implies"

Gompertz revealed in his blog the swearing gave him "a bit of a jolt" when reading the book, "given that she is the world's most famous children's author".

The novel is centred on the death of Barry Fairbrother, whose unexpected passing shocks the local villagers of Pagford.

Publishers Little, Brown & Co said: "Pagford is, seemingly, an English idyll, with a cobbled market square and an ancient abbey, but what lies behind the pretty facade is a town at war."

The company describes the tale as being "blackly comic, thought-provoking and constantly surprising".

Rowling, who admitted being flattered by Gompertz saying it had "something of Dickens" about it, added: "When I did start writing it I was aware that I was doing a contemporary version of what I love, which is a big, fat 19th Century novel set in a small community.

"So to an extent - swear words notwithstanding - that is what The Casual Vacancy is.

"It is a parochial - literally - novel that's looking at slicing through a society with everything that that implies. That's what I wanted to do."

She added that the huge success of of Harry Potter meant she "had nothing to prove".

"I certainly don't mean that in an arrogant way," she added, "I certainly don't mean that I think I can't improve as a writer.

"But Harry Potter truly liberated me in the sense that there's only one reason to write, for me - if I genuinely have something I want to say, and I want to publish it."

Rowling said she will judge the success of this book by "speaking to readers".

When the "hype became insane" with the latter Potter books, she described it as "a monster that was out of control" , adding that "speaking to readers really brought you back to what it should be about".

Her next novel is likely to be for younger readers, although she was keen not to commit herself to anything.

Image caption Harry Potter and the Deathly Hallows Part 2 was the biggest film of 2011 at the UK box office

"I think it very likely that the next thing I publish will be for kids," she said.

"I have a children's book that I really like. It's for slightly younger children than the Potter books."

However, the author admitted she was "proud" of The Casual Vacancy.

"I like it, and if you can say that, however nervous you are on publication day, you're streets ahead of the game," she said.

"Because to put out something you're not that happy with or that you think 'God, I wish I'd had another year to rework it' - and I have been in that position - is very different."

'Odd thing' about Leveson

More than 450 million copies of Rowling's seven Potter books have been sold worldwide.

The novels, about a boy wizard who survives the attack that kills his parents, became a worldwide phenomenon and were turned into eight blockbuster films starring Daniel Radcliffe.

Rowling spoke of the downside of her success, which led to her giving evidence at the recent Leveson Inquiry into media ethics.

"It was a big deal giving evidence to Leveson, because you're in that paradoxical position of trying to stick up for your privacy whilst slightly invading your own privacy," she said, adding she had to think "long and hard" about what to tell the inquiry.

"There were a couple of things that didn't go into the statement," she said.

"Because even though they represented some of the worst things that had happened to me at the hand of the press, or my family, I would have been invading my own privacy quite seriously to talk about them. So that's the odd thing about an inquiry like this."