New details about the treatment of terror suspects in the wake of 9/11 contradict old assurances from former Vice President Dick Cheney that interrogators were "highly trained professionals" who well knew the boundaries of the law. Often, they had received barely two weeks' training and sometimes made up the rules as they went along. The haphazard nature of the CIA's handling of the detainees, especially in the early years of the "war on terror", becomes clear in the internal CIA report released by the US Justice Department. Its publication on Monday coincided with the appointment of a special prosecutor by the Attorney General, Eric Holder.

"How cold is cold?" one officer is reported to have enquired of CIA headquarters, offering just one example of how interrogators were sometimes forced to seek guidance via email or telephone from superiors thousands of miles away in Virginia as they muddled along in the field. "How cold is life threatening?"

Mr Holder agreed to open the new investigation in part because of what he read in the report. Authored in 2004 by the-then Inspector General of the CIA, it described several instances where the actions of the agency's interrogators may have amounted to criminal abuse. Those cases were referred to the Justice Department. In the Bush-Cheney era, the department decided not to prosecute anyone involved.

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Among those expressing dismay at Mr Holder's decision was Mr Cheney himself who insisted again that the CIA's interrogation efforts "saved lives and prevented terrorist attacks".

He went on to say that the hiring of a prosecutor served as a reminder "if any were needed, of why so many Americans have doubts about this administration's ability to be responsible for our nation's security".

The report reveals how the CIA, which had no previous experience of so broad an interrogation programme, was sending people out into the field whose only relevant prior experience was debriefing, which by definition means getting information from people who willingly participate.

Tellingly, it describes how some of those assigned to these missions foresaw even then that there might be trouble for them if what they were doing were ever to leak into the public arena. "Ten years from now we're going to be sorry we're doing this (but) it has to be done," one unidentified CIA officer was quoted as saying.

While parts of the report had been amply trailed, some passages nonetheless elicited fresh shock. One section describes a CIA interrogator telling Abd al-Rahim al Nashiri, charged with the 2000 bombing of the USS Cole, that if he did not play ball, "we could get your mother in here". This, the report says, would have been understood as a threat to sexually abuse them.

On another occasion, another high-level detainee, Khalid Sheikh Mohammed, the 9/11 mastermind, was told directly that the CIA would "kill your children" if any other attacks were perpetrated against the US.

While the CIA's interrogation's programme had a role in foiling potential new attacks, the report says there was no telling whether the harsh tactics used actually helped. Measuring the success of such interrogation is "a more subjective process and not without some concern," it said.

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Yesterday, the UN human rights chief said there should be no immunity. "I hope there is a swift examination of the various allegations... and if they are verified, that the next steps will involve accountability for anyone who has violated the law," Navi Pillay said.

The appointment of John Durham as special prosecutor has already sparked a political firestorm in Washington that may rage for months, possibly creating a dangerous distraction for Mr Obama as he tries to revive his faltering healthcare reform package. It also adds considerable to the miseries of an already-battered CIA.

Its director Leon Panetta finds himself trying to maintain morale while also separating himself from what happened under the Bush-Cheney watch. In an email to worried staff he said his "primary interest... is to stand up for those officers who did what their country asked and who followed the legal guidance they were given."

Torture details: 'We're going to kill your children'

* "According to the interrogator the [blacked out] interrogators said to Khalid Sheikh Mohammed that if anything else happens in the United States 'we're going to kill your children'."

* "The debriefer entered the cell where Al-Nashiri sat shackled and racked the handgun once or twice close to Al-Nashiri's head. On what was probably the same day, the debriefer... revved the drill while the detainee stood naked and hooded."

* "During another incident [blacked out] the same headquarters debriefer, according to a [blacked out] who was present, threatened Al-Nashiri by saying that if he did not talk, 'we could get your mother in here,' and, 'we can bring your family in here'... It was widely believed in Middle East circles that [blacked out] interrogation techniques involves sexually abusing female relatives in front of the detainee."

* One officer expressed concern that one day officers would wind up on a 'wanted list' to appear before a war crimes court due to [their] activities.

Read the interrogation report in full at: independent.co.uk/cia-report