"I am right about the dates. This is not something one gets wrong," he said in a letter to the editor of The Australian released through his publisher yesterday.
Contacted later by telephone in New York, Ms Crichton said she could not discuss the issue until after the Martin Luther King long weekend in the US, and that Beah was unavailable because he was travelling in Europe.
The Australian found many witnesses in Beah's home region in Sierra Leone who said the attacks he claims happened in January 1993 actually took place two years later. Beah, who was born in November 1980, was handed over by the army to a UNICEF-backed rehabilitation camp in January 1996.
The Australian investigated the dates and confirmed the discrepancy while at the same time disproving claims by a man in Beah's home village of Mogbwemo that he was Beah's father.
Beah's parents and two brothers were killed in the war.
In his statement yesterday, Beah challenged one of the witnesses quoted by The Australian, Abdul A. Barry, who was a teacher at the Centennial Secondary School in Mattru Jong when Beah went there in the early 1990s.
Contacted again by The Australian yesterday, Mr Barry said he had no idea why Beah would deny knowing him because "I know him very well".
"He was boarding and I was the boarding master. I also knew his brother Mohamed and their parents. His mother came from Kabati," said Mr Barry, accurately volunteering the mother's home village.
In his book, Beah says his home town, the mine where his father worked and his mother's town were all attacked in January 1993.
He and a group of friends were then waiting in Mattru Jong for news when a Catholic priest was ordered by the rebels to deliver a message telling people inthe town to co-operate with the rebels. Many people fled immediately; two weeks later, the rebels attacked from a surprise inland route, leaving only one unanticipated escape route on a footpath through a nearby swamp.
That is exactly what happened in 1995, according to the adult witnesses, internal records at the mine and numerous published sources.
The 2004 study "Conflict Mapping in Sierra Leone", published by the group No Peace Without Justice, records that a Catholic priest was detained by rebels in December 1994 and ordered to take just such a message into Mattru Jong, prompting the evacuation ahead of the subsequent attack.