They cut off my clothes with some kind of doctor's scalpel. I was naked. I tried to put on a brave face. But maybe I was going to be raped. Maybe they'd electrocute me. Maybe castrate me. They took the scalpel to my right chest. It was only a small cut. Maybe an inch. At first I just screamed ... I was just shocked, I wasn't expecting ... Then they cut my left chest. This time I didn't want to scream because I knew it was coming. One of them took my penis in his hand and began to make cuts. He did it once, and they stood still for maybe a minute, watching my reaction. I was in agony. They must have done this 20 to 30 times, in maybe two hours. There was blood all over. "I told you I was going to teach you who's the man," [one] eventually said. They cut all over my private parts. One of them said it would be better just to cut it off, as I would only breed terrorists. I asked for a doctor.Doctor No 1 carried a briefcase. "You're all right, aren't you? But I'm going to say a prayer for you." Doctor No 2 gave me an Alka-Seltzer for the pain. I told him about my penis. "I need to see it. How did this happen?" I told him. He looked like it was just another patient. "Put this cream on it two times a day. Morning and night." He gave me some kind of antibiotic.

I was in Morocco for 18 months. Once they began this, they would do it to me about once a month. One time I asked a guard: "What's the point of this? I've got nothing I can say to them. I've told them everything I possibly could."

"As far as I know, it's just to degrade you. So when you leave here, you'll have these scars and you'll never forget. So you'll always fear doing anything but what the US wants."

Later, when a US airplane picked me up the following January, a female MP took pictures. She was one of the few Americans who ever showed me any sympathy. When she saw the injuries I had she gasped. They treated me and took more photos when I was in Kabul. Someone told me this was "to show Washington it's healing".

But in Morocco, there were even worse things. Too horrible to remember, let alone talk about. About once a week or even once every two weeks I would be taken for interrogation, where they would tell me what to say. They said if you say this story as we read it, you will just go to court as a witness and all this torture will stop. I eventually repeated what was read out to me.

When I got to Morocco they said some big people in al-Qaida were talking about me. They talked about Jose Padilla and they said I was going to testify against him and big people. They named Khalid Sheikh Mohamed, Abu Zubaidah and Ibn Sheikh al-Libi [all senior al-Qaida leaders who are now in US custody]. It was hard to pin down the exact story because what they wanted changed from Morocco to when later I was in the Dark Prison [a detention centre in Kabul with windowless cells and American staff], to Bagram and again in Guantánamo Bay.

They told me that I must plead guilty. I'd have to say I was an al-Qaida operations man, an ideas man. I kept insisting that I had only been in Afghanistan a short while. "We don't care," was all they'd say.

I was also questioned about my links with Britain. The interrogator told me: "We have photos of people given to us by MI5. Do you know these?" I realised that the British were sending questions to the Moroccans. I was at first surprised that the Brits were siding with the Americans.

On August 6, I thought I was going to be transferred out of there [the prison]. They came in and cuffed my hands behind my back.

But then three men came in with black masks. It seemed to go on for hours. I was in so much pain I'd fall to my knees. They'd pull me back up and hit me again. They'd kick me in my thighs as I got up. I vomited within the first few punches. I really didn't speak at all though. I didn't have the energy or will to say anything. I just wanted for it to end. After that, there was to be no more first-class treatment. No bathroom. No food for a while.

During September-October 2002, I was taken in a car to another place. The room was bigger, it had its own toilet, and a window which was opaque.

They gave me a toothbrush and Colgate toothpaste. I was allowed to recover from the scalpel for about two weeks, and the guards said nothing about it.

Then they cuffed me and put earphones on my head. They played hip-hop and rock music, very loud. I remember they played Meat Loaf and Aerosmith over and over. A couple of days later they did the same thing. Same music.

For 18 months, there was not one night when I could sleep well. Sometimes I would go 48 hours without sleep. At night, they would bang the metal doors, bang the flap on the door, or just come right in.

They continued with two or three interrogations a month. They weren't really interrogations, more like training me what to say. The interrogator told me what was going on. "We're going to change your brain," he said.

I suffered the razor treatment about once a month for the remaining time I was in Morocco, even after I'd agreed to confess to whatever they wanted to hear. It became like a routine. They'd come in, tie me up, spend maybe an hour doing it. They never spoke to me. Then they'd tip some kind of liquid on me - the burning was like grasping a hot coal. The cutting, that was one kind of pain. The burning, that was another.

In all the 18 months I was there, I never went outside. I never saw the sun, not even once. I never saw any human being except the guards and my tormentors, unless you count the pictures they showed me.

Guardian Unlimited© Guardian Newspapers Limited 2005