Novelist J K Rowling has confirmed she plans "not seven, more" Robert Galbraith novels.

Speaking at the Theakstons Old Peculier Crime Writing Festival in Harrogate on Friday night (18th July), in conversation with Val McDermid, the author drew applause from the audience when she confirmed there was an "open-ended" series planned. "I love writing these books. One of the things I love about this genre is that - unlike Harry [the Harry Potter series] where there is an overarching story, here you are talking about discrete stories. So as long as your detective lives you can give him cases."

She added that she knew "a lot" about her private eye Cormoran Strike and where he was going, as well as his assistant Robin.

The Harrogate event is J K Rowling's one and only UK event to promote her new Cormoran Strike novel, The Silkworm (Little, Brown), and in keeping with her Robert Galbraith pseudonymn, Rowling wore a suit and tie to play the part. Her appearance was carefully controlled, with no photographs allowed in the auditorium, and questions from the audience vetted in advance and delivered via McDermid, with whom Rowling shares a publisher.

The author said it was a "no brainer" for her to write crime novels, describing the Harry Potter novels as "six whodunits and one whydunit" - and admitting her "dirty secret" - that she never reads fantasy.

She revealed a love for "golden age" crime - Margery Allingham, Ngaio Marsh, Agatha Christie and Dorothy Sayers, although not Sayers' detective Lord Peter Wimsey - as well as her admiration for Val McDermid herself, Mark Billingham, Ruth Rendell and P D James.

Rowling described the plot of The Silkworm as "probably the most complex plot I've ever written", saying she had the idea for it ahead of the idea for The Cuckoo's Calling, but had decided to keep it for the second novel in order to introduce her series character in the context of a less dense plot. The third novel, which she is a third of the way through, will be "quite different" - "You find out quite a bit more about what happens to people after they leave the military," she said, adding that she had had "a lot of information" on the subject from people who prefer to remain anonymous.

Rowling also talked of her lead character, Cormoran Strike, whose first name is the Cornish for giant, and whose surname, she revealed, she came across by accident, the surname of the author of a book on Cornwall she happened across, immediately recognising it as right. One of the reasons she had made her lead character a war veteran with an amputated leg was that the reality of living with a disability was something close to her heart, she said. "My mother lived with multiple sclerosis, and was latterly disabled - in a wheelchair - and that's day in, day out. We see a vast number of people returning to this country [from war] with disabilities - although the paralympics are marvellous, there is another side. Once you get off the podium you are still dealing with it. It's a pain in the arse. I certainly remember from my mother's experience that when a lift breaks down, for you it's an inconvenience, for someone with a disability... [it's much more]."

Meanwhile she "loved" the character of Robin, she revealed. "I think Robin is the most entirely loveable character I've ever written. A good person but likeable - a smart woman, a kind and loyal person."

On the subject of why she had chosen a pseudonymn and first published The Cuckoo's Calling with no clue as to her true identity, Rowling said: "I wanted to prove to myself I could get a book published on the merits of the book. A friend said, 'Why do you need that validation?' You probably have to be a writer to understand it... I wanted something that was just for me. While it lasted it was a lot of fun." She revealed that she was "jumping up and squeaking for joy" when McDermid's very favourable review of the book was published, and that she even wrote a thank-you letter to McDermid in the persona of Robert Galbraith.

Rowling, who is currently also working on the script for the film of "Fantastic Beasts and Where to Find Them", also hinted at other literary plans, saying: "There are a couple of other things I want to do...mostly novels. There are so many novels I want to write."