Sweden's national obsession with the unsolved 1986 murder of its then-prime minister Olof Palme - renewed this week by a revelation that novelist Stieg Larsson helped police with the investigation - has taken yet another twist after it emerged that a key suspect no longer has an alibi for the night in question.
Palme, a populist, leftwing politician whose views made him numerous enemies at home and abroad, was shot in February 1986 as he walked home with his wife from a cinema in Stockholm. Almost 30 years of inquiries has seen the focus fall on everyone from South African agents - Palme was a vocal critic of apartheid - to rogue Swedish spies.
On Tuesday a Swedish newspaper revealed that Larsson - the late author of the hugely successful Millennium trio of crime thrillers, and an expert on far-right groups - left 15 boxes of files connected to his own probe into the case. Larsson passed police the name of Bertil Wedin, a Swede with links to South African security services, as the man who organised the killing. Wedin, now living in northern Cyprus, denies this and police say he is not a suspect.
However, the newspaper given access to Larsson's files, Svenska Dagbladet, reported on Thursday that its own investigations had brought a new lead about another right-wing activist who was an associate of Wedin. Alf Enerström, a doctor and implacable rightwing opponent of Palme who spent time in a psychiatric hospital after shooting a policewoman, was investigated closely by police but always maintained that at the time of the killing he was at home with his then-partner - an account she backed up.