Wrapped in a blue overcoat on a wet November evening in north London, hands deep in his pockets, white jelabia barely gliding above the pavement puddles, the short figure of Khaled al-Fawwaz appeared an unlikely associate of terrorists. He had arrived in the UK from Sudan in 1994 with the task of establishing a pressure group - the Advice and Reformation Committee (ARC) - supported by Osama bin Laden. The group would lobby for political change in Saudi Arabia. Such goals were barely unique; London at that time had attracted several similar groups which bombarded the Gulf kingdom with faxed messages of protest.

But al-Fawwaz was different. Today, as he fights a US demand for his extradition to stand trial for his alleged involvement in the bombing of the US embassy in Kenya in 1998, his case has been subsumed by the global war against terrorism. Lawyers are debating whether somebody who freely admits to knowing bin Laden should be believed when he makes clear that he rejects the al-Qaeda leader's jihad against the US.

Al-Fawwaz's lawyers argue that the ARC rejected violence, and that al-Fawwaz himself was "shocked" when bin Laden issued his call for jihad. They also say that al-Fawwaz met British security officials while in London, and kept them informed of his activities.

Al-Fawwaz's case has exposed the challenge for the legal systems of the west, in particular the appeals process.

Al-Fawwaz left east Africa four years before the embassy bombings. But if he were extradited, lawyers for the US government would argue in court that he "conspired with bin Laden and others between January 1 1993 and September 27 1998 to murder US citizens in America and elsewhere and to bomb American embassies and other American installations".

They would also accuse him of having "conspired to kill American officials in the Middle East and Africa, to murder American soldiers in US peacekeeping missions and to murder American diplomats and 'other internationally protected persons'."

Behind these allegations lie al-Fawwaz's long involvement with bin Laden and the allegation by the US that his role in London was to create the ARC as a front for al-Qaeda.

Al-Fawwaz applied for political asylum as a Saudi dissident on arrival in the UK, and moved with his family to a nondescript house in Dollis Hill. The asylum application is now on hold.

A year ago the UK's High Court rejected his attempts to have the extradition blocked. He then appealed to Britain's highest court, the House of Lords.

Today, he is waiting to hear his fate. Islam is his life, and while he has fought his case with determination, in the end his view would be that fate is in the hands of the Almighty.

Al-Fawwaz's role as the head of ARC was no secret. Journalists wanting to meet bin Laden arranged to do so through him. He would meet them at a pizzeria in north London's Kilburn High Road, and, after judging their intentions genuine, would invite them to his home.

The faint sound of family life would rise and fall in the upstairs rooms and the kitchen. Visitors would be shown into a sitting room dominated by telephones, computer equipment and a fax machine. In a corner was a plastic model of the grand mosque at Mecca, from which the call to prayer would be issued in a tinny voice, illuminating the model as it did so.

Since the New York trials of the east Africa bombers earlier this year, the bland house, the contents of the sitting room, the street address and the grim suburb of Dollis Hill have all become famous. The trials of the men found guilty of the bombings regularly threw up the name of Khaled al-Fawwaz.

But his story neither started - nor ended - there.

In 1991, bin Laden had moved with 300 of his Arab Afghan fighters to Sudan, which became his base until 1996. While al-Qaeda's activities were developing in Sudan, Al-Fawwaz had arrived in Kenya. He created an import- export company called Asma - his daughter's name - with authorised capital of KSh1m ($1,250).

The company listed as its purpose the import and export of animal hides, agricultural products, fresh beans, coffee husk, and coffee, and to act as "agents, retailers and wholesalers of all commodities, stockists of consumer goods and any other products which may conveniently be dealt with by the company".

The company failed, but US prosecutors at the embassy bombing trials accuse al-Fawwaz of being much more than an exporter of animal hides. They believe he was involved in the reconnaissance of the US embassy in Nairobi, and gathered photographs which bin Laden himself then examined.

Al-Fawwaz's stay in Kenya ended shortly after he had been briefly arrested by suspicious police officers at Nairobi airport. According to evidence from L'Houssaine Khertchou, one of those found guilty of the embassy bombing, al-Fawwaz's travelling companion had raised the suspicion of airport officials because he had a Danish passport.

A Danish-speaking official quizzed him and he was unable to speak the language. Both men were placed in custody. Khertchou said they were released after paying a $3,000 bribe to the police officers.

Al-Fawwaz left Kenya within days, flew to Sudan, and then London and launched the ARC.

While the "name of the president is secret", bin Laden was "one of the establishers of the organisation", al-Fawwaz told the FT at the time. The two kept in contact via a satellite telephone al-Fawwaz bought for $7,500 from a New York company and then sent to Afghanistan.

ARC's role was to voice criticism of the royal house of al-Saud and demand an end to the US presence on the Arabian peninsula. Violence was not on his agenda. "The end doesn't justify the means in our religion. It's against our religion," al-Fawwaz said before his arrest.

He spoke quickly, with an overpowering seriousness, never a flicker of light-heartedness, but with an earnest desire to explain his position, that of ARC - and that of his friend Osama.

"Everybody started to blame Osama for everything and labelling us as a terrorist group. I started to pressure Osama to put an end to this, either by taking the media to court or doing an interview. Then I was made public, as the only spokesman, as Osama was not wanting to meet with the media," he said.

Then came what al-Fawwaz described as a rift with his friend, but which US prosecutors regard as just the opposite. On August 23 1996, bin Laden issued his declaration of jihad against the Americans.

"The declaration of jihad was not the ARC. It's Osama's initiative," al-Fawwaz insisted. "Osama's jihad damaged our campaign. Our aim was to have an economic war [involving a boycott of American products]. But Osama decided to launch jihad," he said at one meeting, switching on his computer and printer, and handing over a full text of the declaration.

"Of course this will mislead people over what I am trying to do. People might think that my campaign was a kind of trick and that people think I was trying to launch jihad. I was worried about this," he said of his readiness to distribute the tract.

Establishing the exact nature of al-Fawwaz's relationship with bin Laden is typical of the challenges now facing the governments, intelligence agencies, police forces and courts seeking to understand the true nature of the organisation.

By handing out copies of what amounts to bin Laden's declaration of war, while saying he disagreed with its contents, was al-Fawwaz a messenger, a clever propagandist or a fool? Since 1998 he has been in a British prison, with much time to ponder this question.

As he awaits the Lords' judgment, he has argued that he did nothing in the UK except exercise his right of free speech, as a dissident seeking asylum. His readiness to exercise those rights was clear when he said: "We had to choose an enemy. So the Americans were the number one enemy. We believe the crisis in Arabia isn't to be dealt with by Saudis alone, because we are the keepers of the two Sacred Places. Our aim is to break the international support for the al-Saud. But I am not very optimistic. And the Americans can only leave after bloodshed."