Jonathan Miller reports: A short drive from the frontier, along hair-pinned mountain roads, past Lebanese checkpoints where friendly soldiers shiver, is a Syrian safe-house. There is no electricity. The place is crammed with refugees; there are children sleeping everywhere. In an upstairs room, next to a small wood-burner, a weathered former tractor driver from Tal Kalakh – who is in his 50s – winces as pains shoot through his battered body, lying on a mattress on the concrete floor. He manoeuvres himself on to a pile of pillows and lights a cigarette. He’s relieved to have escaped to Lebanon but he’s already yearning to go home. He can’t though. His right leg is now gangrenous below the knee; he can barely move. So far he’s had only basic medical treatment.

Before sunrise one morning, he told me, as troops laid siege to his town, he’d been shot twice by “shabiha”, pro-al-Assad militia. Unable to run, he had been rounded up, thrashed and driven down the road to nearby Homs with many other detainees, being beaten all the way. For the next few weeks, his bullet wounds were left to fester, he says, while he was subjected to torture so extreme that his accounts of what had happened to him left those of us who listened stunned and feeling sick. During his time in detention, he had been passed, he claimed, to five different branches of al-Assad’s sadistic secret police, the Mukhabarat.

In flickering candle-light, he told me in gruesome detail of beatings he’d received with batons and electric cables on the soles of his feet (a technique called “falaka”). He had been hung by his knees, immobilised inside a twisting rubber tyre, itself suspended from the ceiling. He had been shackled hand and foot and hung upside down for hours – the Mukhabarat’s notorious “flying carpet”. Then hung up by his wrists (“the ghost”), and whipped and tormented with electric cattle prods.

When he wasn’t being tortured, he had been crammed into cells with up to 80 people, without room to sit or sleep, he claimed. They stood hungry, naked and frightened in darkness, in their filth, unfed, unwashed. He recalled the stench and listening to the screams of others echoing through their sordid dungeon. He told of being thrown rotting food. And of the sobbing of the children.

“I saw at least 200 children – some as young as 10,” he said. “And there were old men in their 80s. I watched one having his teeth pulled out by pliers.” In Syria’s torture chambers, age is of no consequence, it seems. But for civilians who have risen up against al-Assad, it has been the torture – and death in custody – of children that has caused particular revulsion.

The tractor driver told of regular interrogations, of forced confessions (for crimes he never knew he had committed); he spoke of knives and other people’s severed fingers, of pliers and ropes and wires, of boiling water, cigarette burns and finger nails extracted – and worse: electric drills. There had been sexual abuse, he said, but that was all he said of that.

Having finished in one place, he’d been transferred to yet another branch of the Mukhabarat and his nightmare would start all over again. And as the beatings went on day in, day out, his legs and the soles of his feet became raw and infected. That was when they forced him to “walk on rocks of salt”. He told me, speaking clearly, slowly: “When you are bleeding and the salt comes into your flesh, it hurts a lot more than the beating. I was forced to walk round and round to feel more pain.”

He lit another cigarette, then said: “Although we are suffering from torture, we are not afraid any more. There is no fear. We used to fear the regime, but there is no place for fear now.” If the intention of torture is to terrorise, it has in recent months had the opposite effect. Each act of brutality has served, it seems, to reinforce the growing sense of outrage and injustice and has triggered ever more widespread insurrection.