CIA Director John Brennan at a news conference at CIA headquarters in Langley, Virginia. Source: AP

In an unprecedented live telecast from CIA headquarters in Langley, Mr Brennan mounted a stout defence of his officers, saying the vast majority of them did not mistreat prisoners and that torture tended to lead to false intelligence.

But, in the wake of a damning Senate report released on Wednesday into the CIA’s treatment of al-Qa’ida suspects, Mr Brennan confirmed that some interrogators had gone beyond their orders and abused detainees.

Mr Brennan also declassified a letter he sent to Democrat senator Carl Levin that suggested the agency had grave doubts about part of the case made by George W. Bush to justify the war in Iraq.

In the run-up to the March 2003 invasion, US officials including then vice-president Dick Cheney alleged that 9/11 hijacker Mohammed Atta had met an Iraqi spy in Prague before the attacks.

The alleged meeting was cited as evidence of a link between Iraqi dictator Saddam Hussein and the September 11, 2001, attacks on New York and Washington.

But in a letter sent to Senator Levin in March this year and just now declassified, Mr Brennan said field agents had “expressed significant concern” over the report. Senator Levin said yesterday he had asked the CIA to declassify the document to show how the Bush administration “misled” the country before the invasion of Iraq.

The letter said US agents had not established Atta was in Prague — evidence suggests that he was not — at the time he was supposed to have met Iraqi agent Ahmad Khalil Ibrahim Samir al-Ani.

In his press conference yesterday, Mr Brennan said the 2002-09 torture program came amid fear of another wave of violence from al-Qa’ida after the 9/11 attacks, as the agency scrambled to take on a task it had virtually no experience with.

“We were not prepared,” he said, describing how Mr Bush had approved the “enhanced interrogation techniques” now denounced as torture.

Detainees were beaten, waterboarded — some of them dozens of times — and humiliated through the painful use of medically unnecessary “rectal feeding” and “rectal rehydration”.

President Barack Obama halted the program upon taking office in 2009 and has since described the Bush-era use of torture by the CIA as counter-productive and an affront to American values.

“In a limited number of cases, agency officers used interrogation techniques that had not been authorised, were abhorrent and rightly should be repudiated by all,” Mr Brennan said.

Amid a row about whether Mr Bush was right to order tough tactics in the wake of the attacks, Mr Brennan said it is impossible to know whether harsh interrogations had won useful ­intelligence.

“I tend to believe that the use of coercive methods has a strong prospect for resulting in false ­information,” he said.

Mr Brennan said information from detainees was indeed useful in the hunt for Osama bin Laden, but it was impossible to say whether the “enhanced” interrogation had been necessary.

“There’s no way to know if ­information obtained from an ­individual who had been subjected at some point during his confinement could have been obtained through other means,” he said.

According to the Senate report, Mr Bush only learned details of it in 2006, four years after it started in the wake of the 9/11 attacks.

But speaking to Fox News, Mr Cheney denied Mr Bush was kept out of the loop. He said Mr Bush “was in fact an integral part of the program and he had to approve it”.

AFP