The film, Journey, will see Radcliffe play Dan Eldon, a 22-year-old who was among four journalists stoned to death by a mob in Mogadishu in July 1993. Eldon left behind 17 journals, thousands of pictures and a legacy that has won admirers including Madonna and Julia Roberts.
His mother, Kathy, says that she has rejected numerous bids for film rights to the story, and met but turned down leading actors including Orlando Bloom, Heath Ledger, Ryan Phillippe and Joaquin Phoenix, all of whom were eager to play the part. But then she sat down with 18-year-old Radcliffe and his parents at the Four Seasons Hotel in Los Angeles.
'The timing is right and the person is right and I couldn't ask for more,' said Kathy, a journalist, producer and activist. 'He has portrayed a magician for years and my Dan was a different kind of magician. There are parallels in the two Dans' lives. Daniel Radcliffe is a poet, he keeps journals and he's half Jewish. He has a puckishness, sense of humour and energy inside him which remind me of Dan.'
For Radcliffe the role marks a career watershed. He appeared in a TV adaptation of David Copperfield before winning the prize part of Harry Potter in the series of blockbusters based on JK Rowling's novels. But in the past year he has sought to escape Hogwarts' shadow by taking to the West End stage in Equus, appearing nude in one scene, and acting in the film December Boys and the TV drama My Boy Jack
Journey is likely to be a tough test because of the extent to which Eldon and his work still fascinate and inspire. The compilation of his richly textured journals, The Journey is the Destination, has sold nearly 200,000 copies since its publication 10 years ago, and his work now has a permanent home at a new gallery in New York. His mother said that in preserving his legacy she and her daughter, Amy, have enjoyed the support of Trudie Styler, the wife of musician Sting, Alanis Morissette, the singer-songwriter, and Rosie O'Donnell, the comedian and talk show host.
Director Baz Luhrmann and musician Peter Gabriel both expressed an interest in the film, she added. 'Julia Roberts has bought two of Dan's works and been wonderful. Madonna said, "I want to be a Dan fan".'
Eldon was born in Hampstead, north London, to Kathy, who is American, and a British father, from whom she is now divorced. When Dan was seven the family moved to Kenya and he fell in love with Africa. After spells in America and travels worldwide, he followed a family friend to northern Kenya where she photographed refugees of the civil war in neighbouring Somalia. Horrified, Eldon also took photographs which were published in Kenya's leading newspaper.
In 1992, he went to Somalia on assignment for Reuters. He witnessed American and UN troops launch 'Operation Restore Hope', first with a sense of relief, then growing frustration, and his pictures helped draw international attention to the developing crisis. On 12 July 1993, he was due to leave Mogadishu - his bags were packed and his replacement had arrived.
But then UN forces bombed a house where they believed the warlord General Farah Aideed was present. Instead, 74 innocent men, women and children were killed and more than 100 injured. Survivors raced to the journalists' hotel and asked them to take pictures. Travelling in convoy, under the protection of Somalis, Eldon and a group of colleagues went to the bombed compound.
As they began to take photographs, the crowd erupted in anger at what had happened and attacked the journalists. Eldon and his colleagues - Hansi Krauss, Anthony Macharia of Reuters and Hos Maina of the Associated Press - were surrounded, stoned and beaten to death.
'I was in LA, working on a film, and I awakened to this telephone call which changed my life,' Kathy recalled. 'We flew to London and then to Kenya for the service, still feeling numb at that stage. I thought he was gone for ever but I've always felt the tremendous energy of his spirit. I couldn't heal myself until I transformed the horror of Dan's death into some positive things.'
Journey will be directed by Bronwen Hughes, whose films include Harriet the Spy and Forces of Nature, and scripted by Jan Sardi, who gained an Oscar nomination for his screenplay for Shine. Kathy is yet to announce a producer but hopes to start filming next year in Kenya, as Somalia remains too dangerous. Profits will go to the Creative Visions Foundation.
'The film is a teen coming of age story - entertaining, funny, dark at times - but ultimately triumphant,' Kathy said. 'People will leave the cinema feeling inspired, thinking: "Oh my God, let me start living right now!" It won't be pious. We're not trying to idolise him or make him or a hero.'
She said she and Amy burst into tears the first time they contemplated Dan being portrayed on screen. 'A lot of older actors wanted to play this character but we resisted because Dan was a boy emerging into manhood. If you're an established leading actor then you're too old for this role,' Kathy said.
'Daniel Radcliffe is the first time we've found a young enough actor with a global following. We love the way he's a global soul. He's travelled the world and feels comfortable in the world and hasn't been corrupted by Hollywood.'
David Smith in New York/Sunday December 30, 2007/The Observer