CIA agents threatened alleged September 11 mastermind Khalid Sheikh Mohammed with killing of his children if any further attacks on the United States occurred, according to new details released from the CIA's inspector general's 2004 report.
The report was originally issued in 2004 but only a heavily censored version appeared and a judge ordered fuller disclosure.
The report suggests another agent allegedly told a suspect his mother would be sexually assaulted in front of him if he failed to comply with the interrogation.
US Attorney General Eric Holder tonight appointed federal prosecutor John Durham to investigate CIA prisoner abuse cases.
Mr Holder's decision came after the Justice Department's ethics watchdog recommended considering prosecution of Central Intelligence Agency employees or contractors for harsh interrogations in Iraq and Afghanistan that went beyond approved limits.
“I fully realize that my decision to commence this preliminary review will be controversial," Mr Holder said in a statement.
"In this case, given all of the information currently available, it is clear to me that this review is the only responsible course of action for me to take."
As Mr Holder made his decision, new details emerged about the "enhanced" interrogation techniques used after the September 11 attacks on the United States under then-President George W. Bush but subsequently scratched by Obama.
Bush officials, including former vice president Dick Cheney, have denied that torture was used and defended their interrogation practices as legal. These included sleep and food deprivation as well as so-called waterboarding, a technique that simulates drowning, of a handful of suspects.
The administration today revealed it was setting up a new group to interrogate terrorism suspects in accordance with established rules and it will be overseen by the Federal Bureau of Investigation, replacing the CIA in the lead role.
These decisions coupled with more graphic details about interrogation practices, which Obama ordered halted when he took office in January, were likely to ignite a political storm at a crucial time in Washington.
Mr Obama has repeatedly said he wants to move forward rather than dwell on Bush administration actions after the 2001 attacks on the United States. But the White House said the decision was up to Mr Holder.
"The president thinks that Eric Holder, who he appointed as a very independent attorney general, should make those decisions," White House spokesman Bill Burton said in Martha's Vineyard, Massachusetts, where Mr Obama was on a weeklong vacation.
Republicans will likely accuse Mr Obama of being soft on national security while some liberal backers will be upset if the investigation is limited to those who conducted interrogations while excluding the officials who approved the policies.
Mr Obama has been trying to keep attention focused on his top legislative priority -- overhauling the $2.5 trillion health care system. Now, politicians could be distracted with hearings and debate over past interrogation methods.