To his classmates and teachers at the British school in Togo, west Africa, Umar Farouk Abdul Mutallab was the cheerful if sometimes serious student, whose pious views earned him the nickname, the Pope.
But behind his innocent chiding about the perils of alcohol and western decadence
lay a burgeoning pull towards radical Islam, which on Christmas Day, saw him try to take the lives of 278 passengers aboard an American bound airliner.
Mutallab's journey towards terrorism is an unusual one which has shocked and dismayed those who knew him as a youngster.
The son of the former chairman of a Nigerian bank, he enjoyed the trappings of a wealthy upbringing, privately educated in a highly regarded international boarding school.
Among his classmates was the daughter of Karl Hoffman, an adviser to the former US secretary of State Colin Powell.
Mutallab's former history teacher, Mike Rimmer who taught him at the British School of Lomé in Togo, west Africa, remembered him as a model pupil but admitted that he had some radical views in his teenage years.
Mr Rimmer told The Daily Telegraph: "In 2001 we discussed the Taliban in class. All the other Muslim kids thought they were a bunch of nutters with beards, and could not understand why they did such things as banning kite flying. But Umar seemed to think that was reasonable."
He said fellow pupils gave him the nickname ‘The Pope’ because of his "pious" and "high-minded” attitudes and later dubbed him 'Alfa' a local term meaning Islamic teacher
On one occasion, during a school trip to London, Mutallab objected to being taken to a pub for lunch.
The teacher said: "Umar came up to me and said, ‘Mr Rimmer, you should not be taking us into pubs. We do not want to be in a building associated with alcohol.'"
But despite these instances Mr Rimmer remembered his pupil with fondness, saying: "He was very interested in world affairs and would stay behind after lessons to discuss issues. For a teacher, that was just wonderful.
"He was a very personable boy; he could have gone into politics. He could have become the president of Nigeria. But now his future doesn’t look bright at all."
Mutallab's father, Alhaji Umaru Mutallab, 70, is from Funtua in the largely Muslim northern state of Katsina, and retired as chairman of Nigeria’s oldest bank, First Bank, earlier this month after a distinguished career in finance that included 13 years on the board of the bank.
Last night he spoke of his devastation at the news of his son's alleged terror bid. He said: "I am really disturbed. I would not want to say anything at the moment until I put myself together."
After leaving school Mutallab won a place at the prestigious University College London to study mechanical engineering.
His father rented a luxury apartment just off Harley Street and Mutallab surrounded himself with siblings and friends who were part of an elite group of Nigerian ex-patriots in London.
But one friend who knew him in London said he kept himself to himself much of the time and always wore a skullcap, relatively rare among young Nigerian Muslims who usually only wear them on religious occasions.
After graduating from UCL, he moved first to Egypt, and then Dubai in the United Arab Emirates where he studied for an MBA before dropping out and telling his family he did not want to have anything to do with any of them again.
A family friend said Mutallab had made two trips to Yemen for short Arabic and Islamic courses.
Speaking in Kaduna, Nigeria, one of his brothers said he had “extreme views about religion” and had alienated himself from his family members because they disagreed with his views.
The man, who declined to be named, said Mutallab had a number of arguments with his immediate family members over his views on religion and feared he had joined an extremist group in Northern Nigeria called Boko Haram.
"We know Farouk’s extreme views and were always apprehensive of where it may lead him to. He has maintained his distance from us and we never bothered him much. He wanted to be left alone so we respect his wishes. We were always worried about him because he is young," he said.
The brother described Mutallab as "quiet, nice and gentle," adding that he minded his own business and was "morally upright."
But in a series of postings on internet chatrooms Mutallab revealed some of his personal struggles.
In one he wrote: "Can you be my friend? I get lonely sometimes because I have never found a true Muslim friend.”
Later he wrote of joining protests against the war in Iraq, asking: “When is lying allowed to deceive the enemy?” and among his last posts he wrote of heading to Yemen.
Family sources told The Daily Telegraph that Mutallab contacted his them in October from the Yemen, telling them he would be out of touch for seven years.
In interviews with FBI agents Mutallab said he made contact via the internet with a radical imam in Yemen who then connected him with al Qaeda leaders in a village north of the country’s capital, Sanaa.
The student said he lived with the al Qaeda leader in Yemen for about a month and was not allowed to leave as he was trained in what to do and how to explode the device.
At some point, according to the account, Abdulmutallab said he was joined by a Saudi citizen whom he described as an al Qaeda bomb maker.
His family's mounting concern over his behaviour eventually prompted his father to report his activities to the United States’ Embassy in Abuja as well as Nigerian security agencies.
Fabrizio Cavallo Marincola, a 22-year-old mechanical engineering student at University College, who studied with Mutallab said. "We worked on projects together.
"He always did the bare minimum of work and would just show up to classes. When we were studying, he always would go off to pray.
"He was pretty quiet and didn't socialize much or have a girlfriend that I knew of. I didn't get to talk to him much on a personal level. I was really shocked when I saw the reports. You would never imagine him pulling off something like this."