Exposed: Secret and macabre world of jail where thousands were killed

Wednesday was the day for killing and Thursday was the day relatives paid to collect the bodies of the dead. How prisoners were executed depended on an order from above – a bullet to the back of the head for those deemed to deserve a degree of mercy and the rope for those destined to suffer.

On the morning of their deaths, prisoners were asked their permission to be killed: those who agreed first received a glass of water and a brief reading of verses from the Koran while those who said no went straight to the hangman's noose.

These were the workings of the notorious Abu Ghurayb prison, a sprawling complex of barred cells, razor wire and watch towers 20 miles west of Baghdad and, at various times during Saddam Hussein's rule, home for up to 75,000 prisoners. As the closed and secret world of the Iraqi regime continues to give up its secrets, there is perhaps nowhere more disturbing than Abu Ghurayb. "Millions of people were killed here," said a man in a red T-shirt who was walking around the prison yesterday morning with friends who seemed to know in disturbing detail the workings of the execution chamber.

"If the prisoner did not weigh very much then the guards would put their feet on the shoulders of the prisoner and push down to help strangle him." No one has been executed at Abu Ghurayb for many months yet the killing room retains an air of chilling efficiency. The two trap-doors of the gallows have been removed and placed to one side. The executioner's levers still work. The springs were a little stiff but if one pulled down sharply it was easy enough to move the release catches and see how the floor would have fallen away.

How many people fell through the trap-doors of Abu Ghurayb prison is a figure that will probably never be known. Thousands certainly – one former army officer who defected to the West said that 2,000 people were killed here in one night alone. But under Saddam's rule, scores and possibly even hundreds of thousands of people may have met their deaths at the regime's most notorious prison. Two hangman's nooses lay on the floor, the loops of the waxed hemp rope wrapped in white bandages – presumably to prevent the rope from decapitating people.

Nearby lay two black bags used to cover prisoners' heads. There were no steps up to the gallows but rather a ramp. "If there were steps, the prisoner would have known that he head reached the end and may have struggled," said another man.

Abu Ghurayb was no normal prison. While some of the inmates held here were sentenced for "normal" crimes, many were political prisoners – often Shia from the south or else from the slum of Saddam City in Baghdad – sent there for allegedly conspiring against the state.

In the holding cells a number of names and dates had been scratched on to the walls by men waiting to die. Okil. Rashid – 15 March 2002. Sadeq. Sadun. Hassan – 17 November 1999. "There were separate sections for Iraqi prisoners and for those from other countries," said another man, Jomah Mriar, 23, who eventually admitted that he had worked at Abu Ghurayb, carrying in food and provisions for the guards. He had watched the prisoners receive brutal beatings and he had accepted money from them to bring food and cigarettes. Mr Mriar looked nervous, apparently frightened to admit that he had worked at the prison.

His cousin, Mahmood Mriar, said he lived near by and knew that the executions were normally on Wednesdays. On Thursdays he would watch family members come to collect the corpses. "If they had been shot the relatives would only get the bodies if they paid for the bullets," he said. "If not, the government would bury the bodies in a grave with up to 50 other prisoners."

Abu Ghurayb is now silent. In an effort to increase international support, Saddam all but emptied the country's jails last October, keeping incarcerated only political prisoners. These were driven away on trucks, said the two men, two days before the American bombing started. Their whereabouts are unknown.

But even as the regime withered, Abu Ghurayb still had its inmates. Last week two journalists from the US newspaper Newsday were released after being held there for eight days. Last Friday two aid workers were also released after being held at Abu Ghurayb for a week.

American forces are searching Abu Ghurayb for documents that might form the basis of prosecutions. There are plenty for investigators to read through – files full of names and dates and fingerprints as well as hundreds of photographs of men holding cards bearing their names.

They lie on the floors of destroyed offices or else are scattered by the wind in the grounds of the jail.