PALESTINIAN security agents who have allegedly tortured Hamas supporters in the West Bank have been working closely with the CIA, a British newspaper has revealed. The US Central Intelligence Agency has co-operated with the Preventive Security Force (PSF) and General Intelligence Service (GI) in the Palestinian territory, reports Al-Jazeera TV, quoting a report published in the Guardian on Friday. The [Central Intelligence] Agency consider them as their property, those two Palestinian services, a western official told the Guardian. Most of the detained Hamas supporters are held without trial and allegedly tortured by the Palestinian agencies in the West Bank. Hamas backed the Guardians findings on Friday during a Press conference, and blamed Keith Dayton, the US General commanding the Palestinian National Security Force in the West Bank, for the arrest and torture of its supporters. Hamas called on US President Barack Obama to remove Dayton from his position and said Palestinian President and Fatah leader in the West Bank Mahmoud Abbas was responsible for the crimes against Hamas in the West Bank. Human rights organisations say it is common for detainees to be badly beaten and subjected to shabeh, where they are shackled and held in painful positions for long periods. Hamas, which rules the Gaza Strip, has faced allegations that its own forces have detained and tortured people allied with Fatah, a rival Palestinian group that is a member of the Palestinian Authority. Between 400 and 500 Hamas supporters are currently being held by the PSF and GI, officials from the PA have said. But Adnan Aldenari, a Palestinian police spokesman, denied that the security forces in the West Bank were abusing detainees. The Guardian reported that at least three detainees have died in custody this year due to being mistreated. The most recent was Haitham Amr, a 33-year-old nurse from Hebron, who died four days after he was detained by GI officials last June, the Paper said. Shawan Jabarin, the general director of al-Haq, a Palestinian human rights organisation, told the Guardian: The Americans could stop it any time. All they would have to do is go to [prime minister] Salam Fayyad and tell him they were making it an issue. Then they could deal with the specifics: they could tell him that detainees needed to be brought promptly before the courts. A regional diplomat told the newspaper that at the very least US intelligence officers were aware of the torture and were not doing enough to stop it. The CIA does not deny working with the PSF and GI in the West Bank, but Paul Gimigliano, a CIA spokesman, said the US agency does not hold a supervisory role. The notion that this agency somehow runs other intelligence services ... is simply wrong, he told the Guardian. The CIA ... only supports, and is interested in, lawful methods that produce sound intelligence.