WASHINGTON - The Senate Intelligence Committee is preparing to launch an investigation of the CIA's detention and interrogation programs under President George W. Bush.

Activists demonstrate water boarding in front of the Justice Department in Washington DC in 2007. (AFP/Getty Images/File/Mark Wilson) The panel thus sets the stage for a sweeping examination of some of most secretive and controversial operations in recent agency history.

The probe is aimed at uncovering new information on the origins of the programs as well as scrutinizing how they were executed - from the conditions at clandestine CIA prison sites to the interrogation regimens used to break al-Qaida prisoners, according to Senate aides familiar with the inquiry plans.

Officials said the inquiry is not designed to determine whether CIA officials broke laws.

"The purpose here is to do fact-finding in order to learn lessons from the programs and see if there are recommendations to be made for detention and interrogations in the future," said a senior Senate aide, who like others described the plans on condition of anonymity because they have not been made public.

Still, the investigation is likely to call new attention to the agency's conduct in operations that drew condemnation around the world.

It is also bound to renew frictions between Democrats and Republicans who have spent much of the past five years fighting over the Bush administration's prosecution of the war on terror.

The investigation also could draw comparisons to the special Senate committee formed to investigate the CIA in 1975 and headed by Sen. Frank Church, an Idaho Democrat.

Revelations by the Church Committee led to greater congressional oversight and legislation restricting intelligence activities.

The terms and scope of the new inquiry still were being negotiated by members of the committee and senior staff yesterday. The senior aide said the committee had no short-term plans to hold public hearings, and it was not clear whether the panel would release its final report to the public.

The inquiry, which could take a year or more to complete, means the CIA will once again be the target of intense congressional scrutiny at a time when it is engaged in two wars and its continuing pursuit of al-Qaida.

The agency was stripped of some of its power and prestige after coming under severe criticism in previous investigations of its failures leading up to the Sept. 11, 2001, attacks and the war in Iraq.

But while those investigations focused largely on the CIA's error-prone analytic efforts, the new probe will dive directly into its most sensitive operations, seeking to unearth details that previous generations of agency officials referred to as the "crown jewels."

During the Bush administration, the agency was often able to safeguard many of those secrets. Lawmakers have never been told the locations of the CIA's secret prisons, for example.

But the Obama administration is expected to give congressional investigators new access to classified records as well as individuals who took part in operating the secret prisons and interrogating detainees.

CIA Director Leon E. Panetta pledged this week that he would cooperate with any congressional probe.

"If those committees are seeking information in these areas, we'll cooperate with them," Panetta said in a meeting with reporters Wednesday. "I think that we have a responsibility to be transparent on these issues and to provide them that information."