Doctors at the Rafidiyah hospital saw the wound had become gangrenous and wanted to amputate the arm from above the elbow saying it was the only way to save Mr Baba's life. His interrogators refused to let the operation take place and took him back to their headquarters where he died on 31 January.
"He was tortured with the electric element used to boil water and was also beaten with either a stick or an electric cable," says Bassam Eid of the Palestinian Human Rights Monitoring Group.
Photographs of Mr Baba's body taken by his family before they buried him, and given to The Independent, show burns on his upper left arm and thighs as well as red marks indicating that he was whipped on the neck and shoulders.
Mr Baba was the 12th person to die in the custody of the Palestinian security forces since they began to move into Gaza and towns on the West Bank in 1994 under the terms of the Oslo accords. Ten of the prisoners appear to have been tortured to death and two were shot dead in circumstances which are still unclear. Among the 1,200 or more prisoners held in Palestinian jails, torture has become routine.
Some of those tortured were accused of collaborating with Israel, others of belonging to Islamic militant organisations like Hamas or Islamic Jihad, but many were arrested because they had enemies in the Palestinian security forces. Military intelligence is the worst of these, says Husam Khader, a Palestinian Council member for Nablus, who accuses them of being involved "in car theft and other rackets".
At first, the authorities in Nablus, a town of 120,000 north of Jerusalem, tried to keep quiet about what had happened to Mr Baba. His brother Omar, who owns a photographic studio in the town, says: "The first time I knew Youssef was dead was when I heard the news on Israeli radio."
The hospital carried out an autopsy on the body, but the report disappeared. Two nurses from the hospital involved in concealing it are now under arrest.
Nevertheless the circumstances surrounding the death of Mr Baba, a 32- year-old businessman not directly involved in politics, are becoming clear. They show how ordinary Palestinians are wholly at the mercy of the security forces and have no legal recourse.
Mr Khader, who heads an investigation of the affair by the Palestinian Legislative Council, says Mr Baba was "taken to the hospital no less than five times before he died, but the doctors didn't tell anybody".
Mr Baba certainly did not expect to be arrested when he was asked to visit Mahmoud al-Alul, the governor of Nablus, on 3 January. He was involved in a complicated business dispute over land.
His brother Omar says: "He gave some land as security for a loan of $55,000, but when he came to pay the money the man would not give the property back." Other members of the family say that he had arranged a sale of land to somebody who wanted to pull out of the deal. In either case it is clear Mr Baba had offended somebody in Palestinian military intelligence and the governor's office.
For three days, his family did not know what had happened to him. They thought he might have suddenly gone away on a business trip. Then they had an anonymous telephone call saying he was in the military headquarters, a bulky brown building decorated with an enormous portrait of Yasser Arafat, the Palestinian leader, which had housed the Israeli occupation forces until the end of 1995. There, military intelligence - headed in Nablus by Captain Hani Ayad - told the family to apply to the governor, who in turn sent them back to the military headquarters.
Husam Kader, for many years the leader of Fatah, Mr Arafat's political movement in Balata refugee camp on the edge of Nablus, says that Mr Baba was first admitted to Rafidiyah hospital on 24 January because of the injuries he suffered during interrogation.
He says that six days later "the doctors suggested that they save his life by cutting off his arm, but the investigators refused". Bassam Eid confirms that he was told privately by a senior doctor at Rafadiyah that he proposed amputation as the only way of stopping gangrene which had set in. By the following day Mr Baba was dead.
Under public pressure, the Palestinian Authority last weekend arrested Captain Ayad and two of his interrogators as well as Abdel Muti Sadiq, the deputy governor of Nablus, and Bassam Hilu, director-general of the governor's office. But Bassam Eid is not optimistic that this means that Mr Arafat's security forces will be under closer supervision in future. In the past, the heavily publicised death of torture victims has led to summary arrests, but without any change in policy.
There is a feckless confidence in the way the Palestinian security services behave, as if knowing the impotence of their victims to protest against abuses.
In Nablus, last July, Mahmoud Jumayel, a 26-year-old Fatah activist, died after being tortured with electric shocks and continual beatings with electric cable and clubs by members of the Palestinian navy. In December, in Jericho, Rashid al-Fatiani, accused of collaborating with Israel, was shot 13 times though police were uncertain whether he had died because he started a fight or while trying to escape.
Even while Mr Baba was being tortured in Nablus, another prisoner of the Palestinian Authority called Fayez al-Qumseih died of a heart attack in Bethlehem on 17 January.
His son Majdi says: "They beat him with a baseball bat until he confessed."
It is probably too late to curtail the arbitrary power won by the Palestinian security services in the last two years.
The Palestinian media seldom publishes details of torture or other abuses. Protests by leaders of the four main Palestinian human rights organisations - all of whom had campaigned for years against Israeli human rights abuses - have led to their imprisonment.
And Khalid Kidreh, the Palestinian attorney general, who ordered the arrest of Captain Ayad and his interrogators for killing Mr Baba, says that he views all Palestinian human rights activists as "a fifth column".Reuse content