The agency's present director, John Brennan, admitted the CIA made mistakes, but said "harsh" interrogations produced intelligence "that helped thwart attack plans, capture terrorists, and save lives". Senior Democrat Senator Mark Udall called on Brennan to resign. But the White House described Brennan as a "decorated professional and a patriot".
The most serious dispute is over whether the use of torture was an essential component of the intelligence trail that led the CIA to Bin Laden's compound in Abottabad, Pakistan, in May 2011.
The former CIA chiefs say the interrogations were necessary: "There is no doubt that information provided by ... detainees in CIA custody, those who were subjected to interrogation and those who were not, was essential to bringing Bin Laden to justice."
But the report, written by the Democrat majority on the Senate intelligence committee, says the CIA had much of the information that led to Bin Laden before it began its torture programme.
The Senate report also accuses senior CIA leaders of using the killing of Bin Laden to justify retrospectively the torture programme. It says that after Bin Laden's death, senior CIA officers, including then-director Leon Panetta, briefed senators and claimed that the harsh interrogation programme had played a "substantial role" in the operation.
The report concludes that by mid-2002 the CIA had obtained an email address, a phone number and details about Abu Ahmad al-Kuwaiti, the Bin Laden courier who led the CIA to the al-Qaeda leader, from detainees held by foreign governments, before the CIA began torturing its detainees.
The former CIA directors said "information developed in the interrogation programme piqued the CIA's interest in the courier, placing him at the top of the list of leads to Bin Laden".
They also disputed Senate claims that intelligence committee members objected when they learned what the CIA was doing at interrogation sites.
"The briefings were detailed and graphic and drew reactions that ranged from approval to no objection," the CIA directors said.
The Senate report says that several senators, including John McCain who was tortured in Vietnam and is a well-known opponent of torture, had objected to the programme, saying waterboarding and sleep deprivation were torture.
The findings also undercut the narrative of Zero Dark Thirty, the film about the Bin Laden raid which was made with extensive CIA help and helped to build the popular conception that torture was effective. Its director, Kathryn Bigelow, said yesterday that the question of whether torture led to Bin Laden was "complicated".
- Telegraph Group Ltd, AFP
