The Rue Labat in Paris's XV111 arrondisement provides a first-time visitor with a picturesque view of the white dome of the Sacre Coeur, illuminated against the city skyline.

But as he climbed the narrow street on the evening of Thursday December 20, Richard Reid (pictured) had no time for tourism. Walking past an African gifts shop and an Indian restaurant, Reid turned into the Happy Cafe with its welcoming sign offering cheap telephone and internet services.

Ravi, the Sri Lankan duty manager that night, remembers a tall, scruffily dressed and unwashed figure coming in off the streets at round 7.30 p.m asking in English how much it cost to use the internet before sitting at his assigned terminal.

"All I remember was that he looked dirty and didn't want to talk - but that made him no different from most of our clients. The kind of people we get in this area come here precisely because no one takes any notice of them. They ask how much it costs and then they pay," Ravi recalled.

Reid paid FFr65 and stayed bent over his computer for four and a half hours, leaving just before its midnight closing time.

Two days later, on December 22, Reid boarded American Airlines Miami-bound flight at Paris's Charles de Gaulle airport. During the flight, after a crew member saw him trying to use a match to ignite explosives hidden in his shoe, Reid was subdued by fellow passengers.

In recent weeks, investigators on both sides of the Atlantic have been piecing together details of Reid's life right up to the moment he boarded the plan. What has been discovered points to a disturbing development in the threat posed by the phenomenom of al-Qaeda.

French investigators have seized the computer and hard disc and other material containing messages sent by him that night at the Happy Cafe in an effort to shed light on what lay behind his alleged act of terrorism. They are thought to have traced e-mail exchanges involving Reid to a Pakistan-registered internet site in Peshawar which is suspected of having been used as a postal drop for European al-Qaeda operatives.

The son of a Jamaican-born father and a British mother, 28-year-old Reid showed no early signs of political radicalism. But he did have a rough childhood and adolescence. In the mid 1990s he was sent to Feltham young offenders prison, outside London. [WHY WAS HE SENT THERE??] It was there, seemingly unnoticed by his prison wardens, that he underwent the conversion to Islam that was to mark his future.

On his release, he frequented a mosque in Brixton in South London, run by Abdul Haqq Baker, another convert with a Caribbean backround. Brixton was a multi-ethnic community where as one local police officer put it someone like Reid could pass the day and night unnoticed as long as he kept out of drugs and gangland shootings.

Baker recalls Reid as an "affable, amiable" individual on his early visits to the mosque who subsequently became interested in more extreme interpretrations of Islam. In 1998, Reid - who fellow Muslims came to know as Abdel Rahim - was openly mixing with extremists and arguing that jihad - holy war - justified violence.

Investigators have taken evidence from Baker claiming that Reid attended the mosque at the same time as Zacarias Moussaoui, a French Moroccan who has been charged in the US with conspiracy over September 11.

Baker says that he is "pretty confident" that Reid and Moussaoui attended "external study circles" or "extreme scholarship" classes organised elsewhere in Brixton by extremists who were kept away from the mosque and arranged ad-hoc meetings in a local sports centre and a local government building.

Reid disappeared from Brixton about the same time as Moussaoui - in 1998. Within a year he is thought to have made his way to al-Qaeda's Khaldan training camp - Afghanistan's so-called "university of terror".

While it is possible that Reid formally joined al-Qaeda while at the camp, he is thought to have been recruited by supporters of bin Ladin subsequently. The extent of Reid's terrorist skills has also been questioned by security experts who have analysed the bomb he tried to use.

While Reid's appearance as a "loner" initially encouraged theories that he acted alone, this view has receded as investigators have studied his e-mail traffic from the Happy Cafe and his extensive travels prior to boarding the American Airlines, which included visits to Israel, Egypt, Pakistan, Turkey, France, Belgium and the Netherlands. These appear to have been financed by others, as Reid had no income from employment or any other known financial assets.

Following his arrest, Reid is reported to have told US police that he bought explosives from a dealer in Amsterdam who he found through the internet.

The focus is on tracking an accomplice or accomplices who may have been with Reid in Paris, and who may have contacted him in e-mail exchanges thought to have been linked to Pakistan.