Washington (IANS): A scathing Senate report Tuesday slammed the Central Intelligence Agency (CIA) for its “brutal” interrogations of terrorist detainees during the Bush era, saying they delivered no “ticking time bomb” information that prevented an attack.

The majority report issued by the Senate Intelligence Committee also accused the spy agency of routinely misleading the White House and the Congress about the information it obtained from the detention and interrogation of terrorism suspects.

The interrogation techniques – branded by critics as torture – deployed after the Sep 11, 2001 terrorist attack were “deeply flawed” and often resulted in “fabricated” information, according to the report.

Based on more than six million internal agency documents, the report said detainees were deprived of sleep for as long as a week, and were sometimes told that they would be killed while in American custody.

With the approval of the CIA’s medical staff, some prisoners were subjected to medically unnecessary “rectal feeding” or “rectal hydration” — a technique that the CIA’s chief of interrogations described as a way to exert “total control over the detainee”.

CIA medical staff members described the waterboarding of Shaikh Mohammed, the Pakistani mastermind of the Sep 11 attacks, as a “series of near drownings”.

The CIA immediately hit back, saying in a statement that the programme was “effective” and substantially helped its understanding of Al Qaeda’s tactical operations and goals.

President Barack Obama said the report reinforced his view that the harsh interrogation methods “were not only inconsistent with our values as a nation, they did not serve our broader counterterrorism efforts or our national security interests”.

In one facility, a detainee was said to have died of hypothermia after being held “partially nude” and chained to a concrete floor, while at other times, naked prisoners were hooded and dragged up and down corridors while being slapped and punched.

Multiple CIA detainees subjected to the techniques suffered from hallucinations, paranoia, insomnia and tried to mutilate themselves, the report said.

Thousands of Marines at US diplomatic posts and military bases around the world are on alert amid fears the graphic details of how detainees were treated could spark a violent backlash, CNN reported.

Senior members of the Bush administration also voiced disquiet over the release of the report.

Former president George W. Bush told CNN last week that the US was “fortunate to have men and women who work hard at the CIA serving on our behalf. These are patriots”.