DHAKA: CIA Director John Brennan has defended the agency's post-9/11 interrogation methods but admitted some techniques were "harsh" and "abhorrent".
Speaking at CIA headquarters, he said some officers acted beyond their authority but most did their duty, reports BBC.
A scathing Senate report two days earlier said "brutal" methods like waterboarding were ineffective.
Senator Dianne Feinstein, whose committee produced the report, said torture should now be outlawed by law.
In his comments Brennan asserted the CIA "did a lot of things right" at a time when there were "no easy answers".
"Our reviews indicate that the detention and interrogation programme produced useful intelligence that helped the United States thwart attack plans, capture terrorists and save lives," Brennan told a rare CIA news conference in Virginia.
But we have not concluded that it was the use of "enhanced interrogation techniques" (EITs) within that programme that allowed us to obtain useful information from detainees who were subjected to them, he added.
"The cause-and-effect relationship between the use of EITs and useful information subsequently provided by the detainee is, in my view, unknowable."
While he was speaking, Senator Feinstein was rejecting his arguments on Twitter.
One tweet said: "Brennan: 'unknowable' if we could have gotten the intel other ways. Study shows it IS knowable: CIA had info before torture. #ReadTheReport".
Brennan was a senior CIA official in 2002 when the detention and interrogation programme was put in place.
George W Bush, who was US president at that time, has not commented on the report, but his Vice-President Dick Cheney strongly rejected criticism of the CIA's techniques.
"The men and women of the CIA did exactly what we wanted," he told Fox News.
"We said we've got to go use enhanced techniques … and we're going to find out.
"We've got Khaled Sheikh Mohammed who's the mastermind of 9/11 and he is in our possession, we know he's the architect. And what are we supposed to do? Kiss him on both cheeks and say please tell us what you know? Of course not."
BDST: 1335 HRS, DEC 12, 2014
