When Henning Mankell’s detective, Insp Kurt Wallander, first came to attention in Britain, he attracted inevitable comparisons. Nicknamed Inspector Norse, after the famous Oxford detective, he triggered a wave of interest in Scandinavia’s darker sleuths.

Like Morse, Wallander has sparked a tourist trail, with visitors pouring into Ystad, a picturesque medieval town in Sweden. And now, ironically, Wallander’s creator is to visit Woodstock, the home of Morse’s first case. Could this be why the small town has been chosen to host an interview with Mankell, who is visiting Britain to attend the Hay Festival?

Speaking to The Oxford Times from his home near Goteborg in Sweden, the author said: “Obviously, I knew about Morse and Oxford, but I didn’t know about Woodstock. To me, it is a town in the US where there was a pop festival.”

The Oxford Times tried briefly to explain the difference between the two Woodstocks, but there were more important things to talk about. The tenth Wallander book, A Troubled Man, will be the last — a decision that has anguished not just fans of the books, but also followers of the TV series featuring Kenneth Branagh (plus the Swedish TV series shown on BBC4).

The author is apologetic, but firm. “Sooner or later you come to a point when the only thing you can do is put the last dot on the paper. I owe it to my readers never to be writing a Wallander story as pure routine.”

Mankell has created a detective whose character as a melancholic, fallible loner is as compelling as the mysteries he solves. Why is Wallander so gloomy?

“If you speak to the average police officer anywhere in Europe, you will find a gloomy character. Normally, by the end of the day they have seen a lot of very bad things, so obviously they will feel sad. It’s a gloomy world, so obviously life is very bleak for these people, and I understand why they are not happy.”

He claims that this is not a specially Swedish thing. “I don’t think this experience is typically Swedish or Scandinavian. With my late father-in-law, the film director Ingmar Bergman, we used to laugh at the way we were representatives of the Swedish gloom. You can only laugh, because I don’t agree with people who think that this is in any way typical of Sweden.”

Wallander’s final case, in The Troubled Man, is sparked by his move to the country and the discovery that he’s going to be a grandfather. Wallander meets the baby’s father, Hans von Enke, but then Hans’s father, former Swedish navy commander Hakan von Enke, disappears. Wallander investigates, uncovering a Cold War cover-up.

The detective we meet in The Troubled Man has changed since the first Wallander book, Faceless Killers, which is the main topic for the Woodstock talk. It was written in 1994, and the author said: “I have had to go back 23 years. I turned up some old diaries to see what I thought at that time.”

Like other Scandinavian writers, Mankell uses the crime genre to reflect on society. He has strong political views, having been on the flotilla invaded by the Israeli army while trying to break the Gaza blockade. He also works on Aids projects, and for the charity Hand in Hand in India.

“There is always a political dimension in all literature that has any meaning. That doesn’t mean I write manifestos, but I try to look at people in a social and political context. Looking back at my first Wallander, I talk about certain things that make me angry, and that we still haven’t found a solution to.”

At 62, Mankell leads a busy life. Having recently completed a TV and movie script about Ingmar Bergman, he is now checking the proofs of a new novel. It will be his 13th non-Wallander book, so there is plenty for fans to read apart from his detective stories. Half his books were written in Mozambique, where he runs the Teatro Avenida, and Africa is the setting for his latest book.

The author does offer one spark of hope for Wallander fans. “I have left one door open. Wallander’s daughter is a police officer and I could write about her work. I don’t promise, but I could take it on, perhaps after a year. I have left a tiny crack open.”

* Henning Mankell is in Woodstock on May 28 to discuss Faceless Killers for the BBC World Book Club, introduced by Harriet Gilbert. 1.30pm, St Mary Magdalene Church, Woodstock. Tickets, £4, must be booked in advance from The Woodstock Bookshop, 01993 812760.