Stieg Larsson, MI6 and Europe’s biggest murder mystery: who killed Swedish PM Olof Palme? The assassination of the Swedish prime minister in 1986 remains unsolved, but files from the late novelist’s archives could help

All international murder conspiracies eventually lead to London, it seems. The killing of Swedish Prime Minister Olof Palme in 1986 is no different.

According to the author of a book which draws on the real life investigations of Swedish crime writer Stieg Larsson, it’s British intelligence that may hold the key to solving one of the world’s most shocking murders and an open wound in Sweden’s justice system.

Jan Stocklassa, author of The Man Who Played With Fire, has travelled to London this week in the hope of opening up an investigation which began 33 years ago but never found a killer.

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Palme was a charismatic privately educated Social Democrat leader, whose background and style of politics has been compared with Tony Blair’s. Sweden’s domestic politics were never quite enough for him and, like Blair, he loved to take a lead in international affairs.

He used his influence to stand up to America’s war in Vietnam and Soviet Russia aggression in Scandinavia as well as supporting underdogs such as Castro’s Cuba and the freedom fighter movements in El Salvador, Nicaragua and South Africa.

But his methods were rarely conventional and sometimes clandestine which brought him into contact with unsavoury regimes and dangerous groups. By the mid-1980s, Sweden’s prime minister had more political enemies than he had friends.

On 28 February 1986 at 8.30pm, Palme and his wife left their apartment to take the Stockholm underground to the Grand Cinema where they met their son and his girlfriend. After the film, the two couples went their separate ways home.

As the Palmes reached the busy corner of Sveavägen and Tunnelgatan, a man appeared behind them and fired point blank at the prime minister’s head and then shot his wife. Due to a series of emergency miscommunications, there was a delay in an ambulance reaching the scene, and Palme was pronounced dead 47 minutes after the first shot was fired. His wife survived, the bullet only brushing her shoulder.

A few hundred metres across the city, a young Swedish illustrator employed by Sweden’s leading news agency was working late on a graphic attempting to show how Sweden’s economy was controlled by the wealthy Wallenberg family. His name was Stieg Larsson.

Larsson’s investigation

With ambitions of being an investigative reporter, Larsson would become better known for his Millennium trilogy of crime novels that were later adapted for the cinema, including The Girl with the Dragon Tattoo, but only after he died suddenly of a heart attack in 2004.

In 1986, Larsson was also a part-time left-wing activist who had been researching and monitoring far right organisations in Sweden.

The morning after the assassination he was called in to start work on a map of the murder. By the end of the day, Larsson was familiar with the police investigation and the evidence pointing to any suspects or groups who might be responsible.

Larsson, a man with useful contacts, spoke to someone he knew at the Swedish Security Service (Säpo) who told him that an unnamed man had been arrested – and this suspect had been linked to right-wing extremist groups. Larsson’s contact didn’t know the name but described the man’s appearance in great detail.

Larsson was extremely excited by this lead and his casual conversations with his colleagues in the office revealed that he knew more about the case than any of the seasoned reporters. When the police finally announced the name of the suspect, Victor Gunnarsson, ­Larsson was able to link him to the European Workers’ Party, a far-right organisation.

But he needed help. So he reached out to his most trusted friend, Gerry Gable in London, the editor-in-chief of the counter-extremism magazine Searchlight, setting out exactly what he did and didn’t know.

He began his nine-page memo to Gable: “The assassination of the Swedish Prime Minister Olof Palme is, to be perfectly honest, one of the most unbelievable and amazing cases of homicide I have ever had the unpleasant job of covering.”

It was the opening salvo in a life-long pursuit for the truth behind a murder which was to baffle police all over the world.

Since then 10,000 people have been questioned and 134 people have claimed to have carried our the ­murder. A man was even convicted only to be released shortly afterwards on appeal. But in the following years, the investigation has become lost in a forest of evidence, wild conspiracy theories and false leads.

That was until 2014 when another journalist took up the threads of Larsson’s enquiries.

Fast facts: The first suspect

Christer Pettersson, a drug addict who had already been in prison for manslaughter, was convicted of Olof Palme’s murder in July 1989 after being identified by the Swedish PM’s wife in a line-up.

Pettersson appealed over a lack of evidence and was released within months. A prosecutor applied for a retrial in 1998 but failed.

Pettersson was later reported to have confessed. He died in 2004 with many people still believing he was guilty, including Sweden’s current PM, Stefan Löfven. But a new prosecutor appointed in 2016 to re-open the investigation has said that Pettersson was not guilty.

Worthy of a crime thriller

Through Larsson’s former employers, the antifascist magazine Expo, Stocklassa was given exclusive access to Larsson’s voluminous files contained in 20 cardboard boxes.

Stocklassa, who had been working on the story for four years, was at first sceptical about a conspiracy theory to explain the murder of the Swedish Prime Minister.

He tells i: “I was not convinced about any of the theories. But when I started reading Larsson’s painstaking research that quickly changed.”

After weeks of combing through Larsson’s documents and notes, Stocklassa (inset below left) returned to the first letter Larsson wrote to Gable. He now believes that Larsson had discovered the threads of the conspiracy to murder Palme in the first days of his investigation.

Amazingly these leads and connections – which were known to the authorities – were never properly taken up by the police investigation, but they are now explored in Stocklassa’s book, which has become a bestseller in 50 countries and that has now been translated into English.

Larsson had written to Gable: “At moments, it develops with the speed of a Robert Ludlum novel. Other days, it turns out to be more of an Agatha Christie puzzle, only to develop into to an Ed McBain police procedural touched off by a Westlake comedy.

“The name of the victim, the ­political angle, the vanishing face of the killer, the speculations, the dead-end leads, the comings and goings of presidents and kings, the tracking of cars, the rumours and the crackpots and the known-it-all-alongers, phone calls, the anonymous tips the arrest, and the feeling when you think the story is just about breaking – only to end up in nothing but confusion.”

Then in a colossal if prophetic understatement, he added: “Books are gonna be written about this.”

In that first letter, Larsson set out two theories. One was that the Kurdish PKK were responsible. But this was based on the fact that two disloyal members had recently been assassinated in Sweden and that the PKK office in Stockholm was located close to the murder scene. Larsson dismissed this theory as too “racist” and too convenient.

However, he thought the second theory was much more credible. He told Gable of “speculation” that South Africa was responsible for ordering the assassination, adding: “The Palme Commission – of which Palme was a crucial figure – had begun a campaign against arms dealers selling to RSA”.

British links begin to appear

When Stocklassa started examining Larsson’s files, the Swedish journalist discovered that Larsson had spent years amassing evidence linking South Africa to the murder.

He had also identified a number of key figures in the conspiracy who Stocklassa believes Larsson would have interviewed if his life hadn’t been cut short when he had a heart attack while walking up a flight of stairs to work. Larsson was only 50 years old but had led an unhealthy lifestyle of fast food and sedentary investigation.

Socklassa discovered that, in January 1987, Larsson had delivered a 30-page memo to the Swedish police about an alleged “middle-man” called Bertil Wedin. He was an interesting character. A former military officer, officially working in London, writing journalism for the Swedish business community in the early 1980s, he was often seen in the Conservative Monday Club and had developed close links to many influential members of the Tory Party.

Unofficially, Wedin was allegedly providing information to several foreign security services, including Säpo, South Africa’s security agency and the CIA. But crucially he was also well known to MI5 and MI6.

In 1982, the London offices of the African National Congress (ANC) and the South West Africa People’s Organisation were broken into, with documents stolen and handed over to the South African secret service. Wedin was cleared of the burglary, while two other men were given jail terms.

Three months before the Palme assassination, Wedin moved to Northern Cyprus, a country which has few extradition treaties and a history of offering sanctuary to fugitives.

Larsson ­believed that Palme’s public and private opposition to arms being sent to South Africa, in breach of ­international sanctions, had cost him his life.

And the more Stocklassa investigated the case, the more he agreed. He soon discovered that Wedin could have been the “middle man” who had linked South African intelligence to a far-right activist in Sweden who might be persuaded to carry out an assassination.

Wedin had been recruited by Craig Williamson, the former South African intelligence chief under Pik Botha. Thanks to South Africa’s Truth and Reconciliation Commission we now know that Williamson was involved in a series of state-sponsored overseas bombings, burglaries, kidnappings, assassinations during the apartheid era. Britain tried to have him extradited for the bomb attack on the London offices of the ANC which caused considerable damage and injured the caretaker.

Larsson’s papers showed that Williamson had also established a network of informers in Palme’s office in Stockholm.

The more Stocklassa examined Larsson’s theory – that Palme had been assassinated because of his public and private efforts to stop arms reaching the South African government – the more plausible it seemed. Stocklassa used Larsson’s leads to interview both Wedin and Williamson. Wedin is still living in Northern Cyprus in a run-down bungalow. He confirmed to Stocklassa that, ­before working for Williamson, he had provided intelligence on the Soviets to the CIA and MI5 while he was in London. However, he denied being involved in the murder of Palme.

When Stocklassa finally caught up with Williamson in 2015, the South African spy denounced the claims of his involvement as “nonsense”.

Stocklassa’s investigations appeared to have run into the sand. But the Swedish journalist wasn’t giving up.

Could the crime finally be solved?

While combing through the 1999 ­official report into the murder investigation by The Palme Commission Inquiry, Stocklassa came across information about another individual who he believes could hold the key to solving the case.

The day after the assassination, a Swedish agent called Karl-Gunnar Bäck had been contacted by a spy from a Western intelligence service. According to the Palme inquiry, that man worked for MI6.

“This man came urgently to Stockholm the next day and explained how the foreign section of the British intelligence service MI6 had received information that the assassin should be sought among South African contacts, and that there was a connection to South African Arms dealing,” says Stocklassa. “Furthermore a Swedish officer or police source at Säpo was supposedly involved.”

The Palme Inquiry also noted that a Swedish arms company called Bofors had, in the 1980s, been linked to a shady ­British company based in Guildford, Surrey and run by a man who had spent his time between London and South Africa. Could this have been an arms-to-South Africa conduit which Palme was planning to make public?

Stocklassa says despite the provenance of this intelligence, it “was not passed on to the Palme investigation team at the time”. The Palme inquiry papers, seen by i, states that Bofors contacted Bäck and had this line of inquiry closed down.

Stocklassa claims that this is not the only link to British intelligence – saying that either MI5 or MI6 had gone to a great deal of trouble to keep an agent close to Wedin in Cyprus.

He adds that he spoke to the head of the police investigation two weeks ago and was told that inquiries connecting South Africa to the murder were ongoing. He was also told that the authorities had pulled in an unnamed suspect for questioning, partly based on what Stocklassa had discovered and had linked him to a possible murder weapon.

Stocklassa is back in London to see Gable, Larsson’s mentor. But he before that meeting, he says that the key to solving the murder will “come from abroad”.

“I’m sure the British government have ­information about the murder of Olof Palme,” he says, “they must pass on what they know.”

‘The Man Who Played With Fire: Stieg Larsson’s Lost Files and the Hunt for an Assassin’ by Jan Stocklassa (£19.99, Amazon Crossing) is out now