Najwa Bin Laden has published a memoir claiming he was a contradiction of personality traits. She says he was a disciplinarian who would beat his children for showing too many teeth when they smiled, but maintained a passion for sunflowers and fast cars. He also banned the use of electrical appliances in his home and tried to toughen up his sons by making them climb desert mountains without water.

Details from the home life of the founder of Al Qaida have emerged in the book Najwa has written with his fourth son Omar.

Growing Up Bin Laden charts Bin Laden's journey from teenage newlywed to the face of international terrorism, revealing along the way that he was fond of mangoes and the BBC.

Alongside details of his domestic life, the memoir portrays a man who became increasingly severe as he was pursued by the Western powers.

Najwa married her cousin Bin Laden when he was 17 and she was 15 and went on to bear him seven sons, including Omar, and four daughters. Bin Laden went on to take a total of six wives and kept them in seclusion in spartan homes in Saudi Arabia and Sudan where they were not allowed to use electrical appliances, according to the book, which will be published in Britain next month.

The young couple travelled to the United States soon after the 1979 Iranian revolution, where Bin Laden met Abdullah Azzam, the radical Palestinian cleric regarded as his ideological mentor.

Soon after that he began journeying to Pakistan to support the anti-Soviet resistance in neighbouring Afghanistan. He would impress his sons with tales of battles against the occupying Soviet forces during the 1980s, but became increasingly strict on his return from the war. The book also reveals that Bin Laden, who is accused of masterminding the September 11 attacks and remains at large eight years later despite the world's biggest manhunt, had at least one gold-coloured Mercedes and once bought a speedboat.

"Nothing gave him more satisfaction than having a full day to take a speedy drive to the desert, where he would leave his automobile while he took long walks," Najwa said.

Mathematical skill

Forced into exile in the Sudan for denouncing the Saudi royal family's acceptance of US troops in the country, he tried to prepare his family for hardship by making them sleep rough in the desert and climb mountains.

In lighter moments his sons admired his horsemanship and he liked to show off his mathematical ability by challenging people to beat his arithmetic with a calculator.

His son recalls: "My father was so well known for the skill that there were times when men would come to our home and ask him to match his wits against a calculator."

Najwa added: "Osama's favourite undertaking was working the land, growing the best corn and the biggest sunflowers."

Omar Bin Laden, 28, and his mother left Afghanistan before September 11, 2001 and neither is in contact with Osama Bin Laden. Omar married Jane Felix-Browne, a British grandmother from Cheshire, in September, 2006.

— The Telegraph Group Limited, London 2009