Saif al-Islam Gaddafi now scared, alone and pondering his fate

There are no books, and no television. More importantly perhaps, for a partygoer used to shooting weekends at country houses and birthday celebrations, there is no company.

In an anonymous concrete house, in the back streets of the mountain stronghold of Zintan, Saif al-Islam Gaddafi sits alone, with no access yet to a lawyer, friends, or even the four men captured with him.

"For sure, he is just sitting there, thinking about his fate," Osama Jueili, the head of the Zintan Brigade and the man responsible for Saif al-Islam's security, told The Sunday Telegraph.

He does have 20 brigade men on permanent station to guard him. It is doubtful they have much in common with the man who pursued the bright lights of Europe in white tie and tails and once thought he was destined to rule over them.

The capture of the late dictator's son was a happy moment for Libya. A clean operation, it was performed without the bloodlust attendant on his father, Muammar, and brother, Mutassim.

Yet unlike their deaths, Saif al-Islam's fate will linger in the international consciousness for months as he is brought to trial and, most likely, convicted and hanged. Endless questions will be raised – not least by his own lawyers – about his character, his relationship to his father, and his close contacts with politicians and businessmen like Tony Blair, and fellow partygoers Peter Mandelson, Nathaniel Rothschild and Oleg Deripaska.

The process will be a test too of the stability of the new Libya, and of whether a country held in thrall to the whim of one man can unite to the difficult cause of building peaceful, prosperous institutions.

His immediate concern will be the interrogation that awaits him at the hands of a committee of investigators being established by the Attorney General's office in Tripoli, according to both Mr Jueili and the head of Zintan's civilian council, Taher al-Tourki, an urbane lecturer in engineering recently returned from completing a PhD at De Montfort University in Leicester.

But, Mr Tourki said, there was no sign yet of that committee's arrival in Zintan. Nor had he received any instructions from the central government – which swore in a new cabinet only on Thursday – as to how to handle the town's famous prisoner.

Until those instructions were received, Saif al-Islam could not even be granted the single request he is known to have made – to see a lawyer.

So apart from his captors and guards, the only people who have seen him in the week since he was surrounded in a hollow of the Sahara's dunes have been two officials from the International Committee of the Red Cross and a Ukrainian doctor based in Zintan, Andrey Murakovsky.

A brief Red Cross statement said that apart from the injuries to his fingers sustained, according to Saif al-Islam himself, in a Nato air strike in October, he was in good health. It refused to go further.

Mr Murakovsky and Mr Jueili are the only people prepared to discuss the circumstances of Saif al-Islam's imprisonment. Speaking at the town's primitive hospital, the doctor said he was summoned on Sunday morning by Mr Jueili, who drove him backwards and forwards, zigzag like, through the town's backstreets until he no longer recognised where he was.

They drew up at an anonymous, simple house – presumed to be Saif's jail, though even that is not sure – and escorted into a sitting room, where Saif was waiting with a guard.

They spent an hour together. Dr Murakovsky re-dressed his right hand, now missing the top joints of the index finger and thumb and showing signs of gangrene. Mr Jueili said he was hoping to act on the doctor's request to perform a clean amputation before the infection spread, but was concerned about security.

Dr Murakovsky said his patient did not show signs of depression or any other ailment. "He was in a normal condition – maybe a little scared," he said.

Mr Jueili and Mr Tourki justify the secrecy surrounding his imprisonment, and their insistence Saif al-Islam must stay under their control in Zintan, on the lack of security in the capital, Tripoli, where rival militias, including their own, still fight occasional turf battles.

"We are not afraid of pro-Gaddafi supporters," Mr Jueili said. "We are afraid of our own brigades. Of all the militias in Tripoli, each one has its own opinion about Saif – maybe someone will try to harm him."

That secrecy does not mean we cannot know either Saif's immediate future or the outlines of his potential defence.

In a remarkable video filmed on the day of his capture, he is seen lecturing his captors on their folly. He no longer wags his fingers at the camera, but despite his desert robes, he still looks in charge.

He tells the men around him that they have been fooled by Islamists, in particular Abdulhakim Belhadj, leader of the Tripoli Military Council, and his spiritual mentor, Sheikh Ali Sallabi, who has just announced the formation of a new Muslim Brotherhood-style political party for Libya.

He tells them that when these men get their teeth into Libya, they will long for the days of his father again. "Keep on considering them the good guys and me the liar but mark my words you will come to the conclusion, I assure you, that Abdulhakim Belhadj and Ali Sallabi will not bring any good to the country nor to the Libyan people," he says.

"I swear to God, I did too much good to those two guys and they paid me back with betrayal."

The rebels, both their volunteer recruits and their officials, almost universally hold to two certainties about Saif al-Islam's future. He will be given a fair trial in Libya, and he will be found guilty and executed.

For the international community, which will be watching closely, such statements raise the question of what, exactly, are the charges he will face that deserve the death penalty.

One charge, doubtless, will be of corruption, in relation to the personal wealth he and his family accrued. He lived in luxurious homes in Tripoli, Vienna and London, apparently funded from the Libyan state's substantial overseas oil-sourced bank accounts.

Another will be, in some form, of incitement to violence, in particular in two controversial appearances, one on Libyan television on February 20, in which he vowed to crush the "rats", and one atop an armoured vehicle the next month, waving a Kalashnikov and urging on his followers.

But that does not of itself amount to proof of "direction of war crimes", the charge he faces before the International Criminal Court and which, arguably, would be necessary to impose a death penalty even under Libyan law.

"He was making threats, and that's a crime, and he was on top of a tank carrying a machine gun," said Mohammed Salem Drah, a lawyer with a long and courageous record of defending political prisoners before Col Gaddafi's courts.

"But still on that day he raised his fingers, who was he? He had no political position, and he was only expressing his opinion."

Mr Drah said he thought Saif al-Islam would point to his years getting prisoners released from his father's jails – including, as he said in the video, Mr Belhadj – and argue that in defending his father he was doing no more than trying to save the country from civil war.

Amnesty International and Human Rights Watch argue that Saif al-Islam and his trial be moved to the International Criminal Court in The Hague. Mr Drah disagreed but accepted that a court system which for 40 years had been subject to political whim would find it difficult suddenly to summon up the courage to ignore the pressure of public opinion.

That was assuming in any case, he added, that judges decided a legal code based on the principle of upholding Gaddafi family rule could be used to prosecute a family member for doing just that.

"There will be a lot of public pressure," he said. "But we can't just repeat the mistakes of the past after 50,000 people have died. Otherwise we are back to square one."

There are some ordinary Libyans who agree. In the back streets of Abu Salim, the working class district of Tripoli that was the Gaddafi family's power base, there are still proud supporters to be found.

"I want Saif al-Islam as president," said Issam Ali, a 17-year-old reminiscing about attending the demonstrations throughout Tripoli at which Saif al-Islam roused his faithful young followers.

Not all such men are brainwashed teenagers. Mohammed, a security guard who invited The Sunday Telegraph into his home out of fear of retribution from former rebels for his work organising Gaddafi checkpoints during the revolution, was honest enough to admit he had been duped by his former leader.

But he said Saif al-Islam did not deserve what was likely to happen to him.

"I want to see him get a fair trial, not what happened to his father," he said. "He was a good man, who made one mistake."

Many people believe that the government has "secret sources" of information which will provide the requisite evidence.

But for many Libyans, particularly those who fought and saw brothers die, such issues are a legal nicety.

In Zintan, a town of 50,000 always known to be hostile to the Gaddafis, they are looking for consolation for decades of consequent economic neglect. The town's farmers lost most of their animals in the revolution; its shops, most of their business.

The situation is bleak. But not quite as bleak as Saif al-Islam's. In the town's arms depot, the men guarding scores of tanks and other armaments left over from the war had little time for sympathy.

Mahmoud al-Hashimi, 25, an oil industry worker, and Mohammed Lashtar, an accountancy student, fought their way from the mountains to Tripoli and were in no mood for mercy.

"He is going to be put on trial and they will execute him because he has committed crimes against human rights, and that is indeed what should happen," Mahmoud said. "It's impossible he could be found innocent. If he's acquitted, I'm emigrating."

"And I'm on the plane with him," said Mohammed.