Bryan Appleyard's full account of his interview with Ishmael Beah

"How many people did you kill?"

"I've no idea. I really don't know. I was in it for quite some time, each day of the war we were fighting or there were exhibition killings. When we captured prisoners, it wasn't like real; war where you take them to prison. We lined them up and… it was a way of indoctrinating new recruits."

The book is brilliantly written and horrifying. It captures the complex of pity and terror evoked by the idea of a child soldier - pity for the lost childhood, terror at our own awful intuition that a child will make a uniquely brutal killing machine. The book was well-reviewed and sold 650,000 copies in the US. As a result, Beah became a global advocate for UNICEF (United Nations Childrens Fund).

But then, last year, Bob Lloyd, an Australian mining engineer, visited Sierra Leone. He knew about the book. He came up with what he thought was some good news. He had found Beah's father - in the book Beah says he was killed by the rebels. But it was not good news for Beah's publishers because the discovery started a process whereby his story seemed to unravel.

The story came to the desk of Peter Wilson, the London-based Europe correspondent of The Australian newspaper. He travelled to Sierra Leone and established at once that the man Lloyd had met was not Beah's father. It was a misunderstanding about how familial relationships are described. But Wilson found more substantial reasons for doubt and has now published a series of stories calling the whole of Beah's narrative into question. The crucial issue is that Wilson has provided evidence that Beah's ordeal began not when he was 12 but when he was 14. This would make his claim of a year on the run plus two years in the army impossible since it is known for certain that he was picked up by UNICEF when he was 15 in January 1996.

Yesterday (Saturday) in The Australian Wilson published further evidence from teachers who say Beah was definitely at school for two years longer than he says in the book. He also reported a potentially crucial development. On Friday morning two teachers going through papers at the school unearthed academic results covering the period between January and March 1993. The fact that these results exist at all mean the school was not attacked in January. Furthermore, the results include the marks of Ishmaerl Beah. He cam second in his class, good at English not so good at maths.

Wilson has also invesigated an incident in the book - a fight between boys from rival factions at a UNICEF Rehabilitation Centre in Freetown that ended with six dead. UNICEF has been able to find no evidence for such an incident.

I asked them for a comment on all this. They issued a statement.

"UNICEF is not aware of any discrepancies in Ishmael's story. Ishmael himself has categorically denied them. It is our view that even one day as a child soldier is one day too many…."

This is, to say the least, unhelpful, Thanks to Wilson, UNICEF is fully aware of discrepancies and to say that 'one day as a child soldier is one day too many' is to imply that the organisation is less interested in truth than in rhetoric. A similarly unhelpful blunder was made by Dan Chaon who was Beah's creative writing instructor at Oberlin Colleg in Ohio who said, "If it turns out there are factual errors, I wouldn't necessarily be all that concerned about it."

And, finally, Beah's British publishers, Harper Perennial have made matters even worse with what I think is the grossest error I have ever seen in a book from a major publishing house. In the front of the UK paperback there is a map of Sierra Leone. The accompanying scale suggests the straight line distance from the coastal border with Guinea to the Liberian border is about 1200 miles; in fact it is 200 miles. The whole map is wrong by a factor of five or six and, Wilson points out, the location of a crucial village is completely wrong. The effect is to make Beah's wanderings, traced on the map, look much more prolonged than they were or could have been.

I asked Wilson what he thought was going on here. He believes that 'at every step of the way Ishmael was given incentives to exaggerate his story'. At school he was a bright pupil with a gift for language. In Freetown a UNICEF nurse encouraged him to tell tales and reward him with, among other things, a Walkman. He won a trip to New York in 1996 with his graphic descriptions of life in the war. There he met Laura Simms, a writer and storyteller and the woman he now calls his mother, who helped him make his narratives more vivid and, finally, at Oberlin, Chaon spotted his literary gifts, not necessarily as reportage but as the product of a vivid imagination.

Is this the whole story? Beah is dismissive of the questions he is now being asked almost daily - Wilson has been following him around London all week. So far he has not dealt with specific detail, but has issued a broadly dismissive statement. His first point to me was the anguish caused by the false father story.

"They never actually apologised to me for dragging me through that emotional thing…. Instead, every other day now - I go on The Australian web site to read it - they have a new instalment. This is what I think: they went and they didn't find anything so they tried to find something else just to discredit me…."

On the incident at the UNICEF centre he says, "Whose word do they have for saying it didn't happen? First of all they said there we an official in government who said he didn't want to disclose his identity. They said if this thing happened they would have known about it. Then I think to myself - Sierra Leone, do they know how many children were killed in the war? Does the government know or care about that? Of course not."

A clear possibility is that the sheer success of the book and the celebrity of its author is driving a combination of envy and, in the small world of Sierra Leone, a desire to be part of the story.

"If you go round waving a book in Sierra Leone and asking, "Who knows this person?' somebody is going to say, 'Of course, that's my son or could be my brother, who knows?'"

But he says he doesn't want to fight the allegations as it would be like "throwing petrol on the fire."

"I don't worry about it. For me, my story is accurate and I presented it accurately and I stand by it. I'm not worried about it."

He is an extraordinary man, plainly brilliant and, though his schooling was cut short at either 12 or 15, very well educated. He was brought up a Muslim. But Sierra Leone in those days was a pleasant, laid-back, religiously tolerant place and he went on to a Christian school.

"It was very loose. I went to a Muslim school and said my Friday prayers and then went to a Christian school and read the Bible. You would go to wedding where there was a Muslim man and a Christian woman."

Apart from Shakespeare, his big early literary influence was rap music. Even when very young, he earned a reputation for writing rap lyrics which he would recite at local talent contests.

"Those were the days when rap made sense, you know? I still love the music but it's quite hard to defend these days."

And, even if Wilson is right and his story is wrong or exaggerated, he was, without question, a witness to one of those vast and terrible African bloodlettings before which, it seems, we can only wring our hands and spout pieties. I ask him how he feels about Africa as a whole.

"There's a lot of problems there. But I haven't given up hope. That's one of the reasons I have written this book - to show the context in which war comes about… The problem is there's a lot of corrupt leaders willing to embezzle funds. The people are not asking for much, they just want simple lives…"

Sierra Leone was Tony Blair's first foreign adventure. Just 800 British troops stopped a further outbreak of civil war in 1997. Beah agrees it made a strong case for intervention but criticises Blair for not acting sooner.

Wilson isn't accusing Beah of any great wickedness. Memory - especially that of a teenage boy high on drugs in a war zone - can be wildly distorted by extreme experience. Wilson himself was held prisoner in Baghdad under Saddam. He told friends it felt like three years but it was only three months. In fact, when he consulted his notes, he found it was only three weeks. Something similar, he believes, happened to Ishmael Beah.

So do we have here a reformed mass killer, a man with a drug-scrambled memory or a brilliant young storyteller? I only know what I have been told by a very diligent reporter and a man with a childlike face and a hypnotic gaze.

A Long Way Home: The True Story of a Child Soldier by Ishmael Beah is published by Harper Perennial at £7.99

www.bryanappleyard.com