Hakan Nesser laughs a lot. It’s not what I expect from an author whose fictional detective rivals Inspector Wallander in the pessimism stakes, but Nesser finds plenty of things to be amused about, reeling off anecdotes and cheerfully recalling reader responses to the gruesome deaths in his books. His novels starring the lugubrious Detective Chief Inspector Van Veeteren have been adapted for Swedish television, and he was once recognised by a woman in the local post office. “I’m so glad she killed him,” she exclaimed, referring to the previous night’s episode, in which a female serial killer clocked up another victim.

“You are in morally deep waters,” Nesser acknowledges. “It’s written that way so you sympathise with her.” The novel on which the Swedish television series was based, Woman with Birthmark, has just been published in the UK, offering British readers a taste of the devious plots and moral ambiguity at the heart of Nesser’s appeal. The novel pits Van Veeteren against a woman taking lethal revenge on a group of men who wronged her mother many years ago; the murders are graphic, a shot to the head followed by another in the groin, and the viewpoint switches between the investigation, the next victim and the killer with dizzying rapidity. Readers find themselves torn, want­ing justice to prevail, but secretly cheering on the killer.

It’s set to become Nesser’s breakthrough novel in this country, and he is being favourably compared with Henning Mankell and Stieg Larsson. Those two writers have almost single-handedly destroyed Sweden’s reputation for cheerful pop and colourful kitchenware. The country’s proud social-democratic credentials are under strain in Mankell’s novels, while its secret Nazi past is exposed in Larsson’s Millennium trilogy, along with present-day sex trafficking in Stockholm and the influence of Russian gangsters.

Their success is staggering in the UK, where translated fiction doesn’t always get a friendly reception. They are part of a Swedish cultural invasion that has seen Mankell’s novels become bestsellers, despite being set in a provincial town in southern Sweden. Last month’s Bafta awards confirmed Wallander as the new Inspector Morse; it won best drama series and was voted onto the shortlist for the people’s choice award. Even at the multiplex, Sweden is finding mainstream success, with the stylishly creepy vampire film, Let the Right One In.

Larsson’s first novel, The Girl with the Dragon Tattoo, was turned down by half a dozen mainstream British publishers before being snapped up by Christopher Mac-Lehose, the man who spotted Miss Smilla’s Feeling for Snow, and becoming a surprise bestseller. This year, the second volume in the trilogy, The Girl Who Played with Fire, became the first translated novel to top the hardback fiction chart in this country. Larsson is currently the most widely read novelist in Europe.

So, what is it about these Swedish imports that we find so seductive? Maybe their relentlessly bleak view of the world makes us feel that our lives are better than we imagined, allowing us the pleasure of wallowing in pessimism at a safe distance. It has to be said that a meeting between Wallander and Van Veeteren would constitute an epic encounter of depressives, requiring a team of counsellors to be on hand. “Was the bottom line that it was more difficult to handle things by the sea?” Van Veeteren ponders halfway through a case. “Did this endless grey mirror make everything incomprehensible and impossible to master? Make this case so totally hopeless?”

There’s no doubt we love this Nordic anguish, but when I ask Nesser whether Swedes are really like that, he guffaws with laughter: “It’s a stereotype!” He was in New York when the Swedish film director Ingmar Bergman died — Bergman was Mankell’s father-in-law, incidentally — and was amused by the assumptions that informed the obituaries.

“Nordic people are supposed to be depressed,” he says. “We’re not supposed to talk at all. We’re supposed to keep everything inside.” This is, he admits, a useful device for crime novelists; people who store things up for 30 years are more likely to reach breaking point and run amok than reflective types who can tame their demons.

It’s not quite clear whether Van Veeteren’s depression is specifically Swedish. The name is Dutch, and Nesser never identifies the country in which his fictional town, Maardam, is set; it seems to be an amalgam of Sweden, the Netherlands and Germany. In the original, he switches between Swedish and Dutch versions of common words such as street, even putting in “deliberate” mistakes to maintain the confusion.

When I ask how he came to invent Van Veeteren, his answer is disarmingly frank: he didn’t set out to write crime novels, he says, and he certainly didn’t try to invent an original detective. “I just had one story, and I wanted to tell it. I realised I needed a detective, and I wanted to make him classic, just like Morse — a classic depressed Swedish hero.” He has stayed with the character for 10 novels, a reminder that while Nesser is the new boy on the block for British readers, he started writing long before Larsson and has won prize after prize in Sweden.

Born in 1950, Nesser spent much of his life in Uppsala before moving first to New York and then to London with his psychiatrist wife. He speaks perfect, unaccented English and taught English and Swedish history until he became a full-time writer. His preoccupation with feeling and motive suggests a background in psychoanalysis, but he says he just reads a lot. “What you are doing is digging into the soul of a human being. If you write seriously, you are interested in why people do things. You can get your explanation from Freud or something else.”

When I ask him what he has in common with Mankell and Larsson, he answers impishly: “We all write in Swedish.” He’s given the question some thought, though, and sees himself as the odd man out. “Henning and Stieg Larsson are closer. Larsson is political. I’m also on the left, but I can’t write political stuff. It’s difficult to create a good story — you start with someone committing a series of murders, then you find out he was mistreated as a kid. It’s too simple.”

Nesser’s novels are nevertheless full of people who have been abused, raped and destroyed by drugs, and Van Veeteren spends a great deal of time getting inside the mind of their abusers. In Borkmann’s Point, a startlingly clever mystery that won the annual award for best Swedish crime novel, the policeman unwittingly forms a close friendship with a serial killer, who eventually kidnaps one of his detectives.

In some ways, it would be more accurate to describe Larsson as the odd man out. One of his main characters is a journalist, the other a female hacker, and they’re younger and more cosmopolitan than Wallander and Van Veeteren. Yet Larsson’s extraordinary personal story may have inadvertently reinforced the idea that Sweden is a place where bad things happen; he delivered all three novels and died suddenly at the age of 50 without seeing their success, a sequence of events Nesser des- cribes with feeling as a “tragedy”.

Another factor in Sweden’s troubled contemporary image is the assassination of the country’s prime minister, Olof Palme, as he walked home from a Stockholm cinema with his wife in 1986. The crime remains unsolved. Another politician, the foreign minister Anna Lindh, was murdered 17 years later in a Stockholm department store. Mankell wrote a novel about just such an assassination, and shares Wallander’s pessimism about his country’s future in an increasingly globalised world.

Nesser appears to have been blessed with a more sanguine temperament, but his fictional world is about as noir as it gets, prowled by monsters who drown women in the bath and tormented souls bent on revenge. “I try to be sincere,” he says alarmingly, leaving me to reflect on how many axe murderers there seem to be in Sweden these days.

Woman with Birthmark by Hakan Nesser is published by Macmillan at £16.99

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