Ernest Hemingway’s troubled life and tangled loves have fascinated readers throughout the decades since his suicide in 1961. Now a new book promises to provide the definitive word on the writer’s time in 1920s Paris.

Focusing on the tumultuous period when he split from his first wife Hadley and took up with American journalist Pauline Pfeiffer, Between Two Women: Hemingway in Love, a memoir by long-time Hemingway confidant AE Hotchner, draws on years of taped interviews between the two men. They include several long conversations in the last weeks of the writer’s life, and paint an evocative picture of a man tormented by the memories of his first marriage and the notion that he had never been as happy as he was when young and impoverished in Paris.

The book also touches on the author’s relationships with his third and fourth wives, war reporter Martha Gellhorn and journalist Mary Welsh, and his three sons, Jack, Patrick and Gregory, in addition to painting a fascinating picture of his intense, complex friendship with fellow writer F Scott Fitzgerald.

Hotchner, now 94, was something of a fourth son to Hemingway, spending many hours in conversation with the author during his later years, a period he wrote about in his first memoir, Papa Hemingway, in 1966. It was published five years after Hemingway, newly released from the Mayo Clinic where he had been treated for depression and paranoia, shot himself at his home in Ketchum, Idaho.

Certain conversations were omitted from that memoir out of sensitivity to those still alive, and it is these communications, often dark and obsessive, sometimes sharply funny, always passionately alive, that Hotchner recounts in Between Two Women. “What makes this book extraordinary is that it’s the last chance we have to hear from someone who had that connection with Hemingway, who sat and talked to him,” says Paul Baggaley, publisher at Picador, who will bring the book out in the UK this autumn. “It’s a very compelling story, not least because the author has given an initial account so long ago which first set up the myth of Hemingway, and this can be seen as both a companion and also a corrective in some ways.”

However, not everyone is convinced that the version presented in Between Two Women, which states that Hadley was the true love of Hemingway’s life and the relationship with Pauline a disaster, should be accepted as gospel. “Ultimately it’s just one side of the story, Hemingway’s side,” says Naomi Wood, whose recent novel, Mrs Hemingway, is a meticulously researched look at the author through the eyes of his four wives. “The love letters he sent to Pauline were just as emotional and sentimental and desiring as the ones sent to Hadley. He was in love with Pauline in 1927 but she never gets redress [Pfeiffer died suddenly in October 1951]. Hadley spoke to several of the biographers, Martha Gellhorn had her own status, and Mary wrote a memoir. Pauline is the only one who never has a say. It’s also hard to say how much his conversations towards the end are fuelled by nostalgia, paranoia and depression. Earlier in his life he was a bit more balanced about what occurred.”

Ernest Hemingway with his second wife Pauline. Photograph: SNAP/REX/Shutterstock

Sarah Churchwell, professor of American literature at the University of East Anglia, and author of the critically acclaimed Careless People, which looks at the origins of The Great Gatsby, argues that while Hotchner’s perspective is valuable – “on one hand he knows what he’s talking about: he was there at the end” – it is also important to remember that “Hemingway was revising history in the last years of his life with a vengeance… there is myth-making and axe-grinding all over A Moveable Feast [Hemingway’s late collection of sketches of life in Paris].

“I think he loved Hadley, I think he knew he betrayed Hadley, and I think he spent many years at the end of his life trying to reconcile memories of his idealistic, romantic, younger self with the despair and disintegration he was facing.”

One thing everyone can agree on, however, is that the fascination with Hemingway, Fitzgerald and the Lost Generation shows no signs of abating, with several novels, a movie and a film on Hemingway’s life by documentary master Ken Burns all in the works.

“It’s the appeal of a gang of successful, talented people all hanging out together,” says Liza Klaussmann, whose recently published second novel, Villa America, tells the story of Sara and Gerald Murphy, the inspiration for Fitzgerald’s Tender is the Night. “We’ve gone through a recession, and austerity and belt-tightening makes everything seem kind of drab, thus there’s a great deal of nostalgia for this gilded era when everyone is drinking and throwing money around. There’s a letter that Fitzgerald sends the Murphys when they are at their lowest, saying ‘the golden bowl is broken but it was golden’. I think that’s what we respond to; the idea that this was a beautiful world, and when it crashed it did so spectacularly.”