Stieg Larsson's final novel '70% complete', colleague claims

The fourth novel by Stieg Larsson, author of the 30m-selling Millennium Trilogy, is 70% complete, strongly features Camilla Salander, the twin of the series' protaganist Lisbeth, and is set "between Ireland, Sweden and the US", according to Larsson's former colleague Kurdo Baksi.

Baksi, who was speaking at the Edinburgh international book festival about his memoir, Stieg Larsson My Friend, claims to have been shown the draft novel by Larsson's partner of nearly 30 years, Eva Gabrielsson, shortly after the author's death. Larsson died of a heart attack in 2004, before the novels were published.

However Baksi's claims about the fourth book are sharply contradicted by Gabrielsson herself, who has said that the novel, at about 200 pages, is only about 30% complete and does not "hang together". It exists in draft form on his computer, which she has kept.

Baksi said: "It is at 260 pages at the moment – about 70% complete. Eva has said the book is not so complete. She took the book after Stieg died and showed it to me and his father."

Gabrielsson, who has also written a memoir, has previously hit out at Baksi's representation of Larsson as a sloppy journalist who was not above rigging the facts, describing Baksi's book as "pure slander" and calling for it to be withdrawn.

Larsson's family – who inherited Larsson's estate after he died intestate – have previously offered Gabrielsson Larsson's share of the flat they co-owned in return for the computer, an offer that Gabrielsson refused.

Baksi, a Kurdish-born journalist colleague of Larsson's and a former winner of the Olof Palme prize, said that the manuscript as it stood would "make the perfect Hollywood film" but argued that an attempt to complete it posthumously would be inadvisable, as putative ghost writers "would not respect Stieg Larsson's style". Baksi claims that there were 10 novels planned by Larsson, and the "fourth" novel is in fact sequentially the fifth.

On his relationship with Gabrielsson, he said: "She asked me, 'Are you with me or with the family?' And I said I am not with you, and not with the family. I have known his brother for a long time, I feel part of the family. I want to be a friend to both you and them… The first two years I was with her, I did everything for her, speaking with the lawyers, talking to her every night. But I can't not say hello to the family."

He added: "Eva was not the only woman in his life. He had some moments here and there – I know of four of them. You don't need to worry about Stieg Larsson. He had a good time in his life."