A new report from a human rights group accuses the CIA of using harsh interrogation measures on detainees who were subsequently imprisoned in Libya and cites claims by one former detainee that he was subjected to waterboarding.

The report, by Human Rights Watch, is based on accounts from Libyans who allege that they were tortured by the CIA in Afghanistan, transferred to Libya in 2004 and held in that country’s prison system until the uprising against dictator Moammar Gaddafi last year.

The accusations are broadly consistent with previous accounts of the CIA’s treatment of prisoners in the years following the Sept. 11, 2001, attacks. But at a time when the controversy surrounding that program seemed to be slipping into history, the report raises a new challenge to the agency’s long-standing contention that only three prisoners — all of them still in custody at Guantanamo Bay, Cuba — were ever subjected to simulated drowning as an interrogation technique.

Documents: CIA rendition to Gaddafi's Libya

The CIA did not directly dispute the new waterboarding claim.

“The Agency has been on the record that there are three substantiated cases in which detainees were subjected to the waterboarding technique under the program,” CIA spokeswoman Jennifer Youngblood said in a statement. “Although we cannot comment on these specific allegations, the Department of Justice has exhaustively reviewed the treatment of more than 100 detainees in the post-9/11 period — including allegations involving unauthorized interrogation techniques — and it declined prosecution in every case.”

As part of the report, researchers with Human Rights Watch also recovered files from the offices of Gaddafi’s former spy chief that provide a remarkably direct glimpse into the CIA’s “rendition” program, in which the agency delivered dozens of detainees to countries, including Libya, notorious for their records on human rights.

“The scope of Bush administration abuse appears far broader than previously acknowledged,” said Laura Pitter, counterterrorism adviser at Human Rights Watch and the author of the report, “Delivered Into Enemy Hands: U.S.-Led Abuse and Rendition of Opponents to Gaddafi’s Libya.”

The 154-page report includes testimony from 14 Libyans who emerged from that country’s prison system after rebels surged into Tripoli in August 2011. At least two of the former detainees now serve in significant roles in the fledgling Libyan government.

Five of the prisoners interviewed by Human Rights Watch described being turned over to Gaddafi roughly a year after he abandoned his illicit weapons program in 2003 and sought to recast himself as a counterterrorism ally of the United States.

Two of the 14 detainees claim to have been doused with water to induce suffocation.

Khalid al-Sharif, who says he was held at the CIA’s facilities in Afghanistan, described being forced to lie down on plastic sheeting as guards hoisted the edges and filled up the makeshift basin with frigid water. After he was hooded, “they poured the water over my mouth and nose so I had the feeling that I was drowning. I couldn’t breathe,” Sharif said.

The second prisoner, Mohammed al-Shoroeiya, said he was subjected to similar treatment in Afghanistan, but he also described being strapped to a board that was mounted on posts and could be dipped backward so that his feet were elevated above his head. “Then there is the water pouring,” he said, according to the report. “They start to pour water to the point where you feel like you are suffocating.”

A 2004 investigation by the CIA inspector general documents other abuses in Afghanistan but makes no mention of a waterboard. The findings of a multi-year probe by the Senate Intelligence Committee have yet to be released.

The CIA maintains that only three prisoners were ever waterboarded: Khalid Sheik Mohammed, Abu Zubaida and Abd al-Rahim al-Nashiri. Former agency officials said that those sessions took place at secret CIA sites outside Afghanistan and that the agency restricted the use of such techniques to controlled environments far from the war zone.

The documents recovered from the offices of Gaddafi’s former spy chief and foreign minister, Musa Kusa, trace the U.S. embrace of Gaddafi as a counterterrorism ally during the brief window after he renounced his chemical weapons program but before the United States turned on him again last year.

A 2004 message describing the CIA’s plans to open a station in Tripoli was sent by “Mr. Steve,” an apparent reference to Steve Kappes, the agency’s former deputy director. Another fax offered to help pay for Libya to charter a plane to pick up a prisoner in Hong Kong — a remarkable accommodation for a country accused of plotting the 1988 bombing of a Pan Am flight over Lockerbie, Scotland.

The pages outline often-elaborate plans for delivering to Gaddafi’s government prisoners who were part of an Islamist group that fought for his overthrow. The documents include requests for direct CIA access to the prisoners and assurances that they wouldn’t be mistreated.

“Our officers cannot condone any significant physical or physiological” abuse, said a March 2004 document that describes plans for “the capture and rendition” of Libyan Islamic Fighting Group leader Abdullah Al-Sadiq “and his pregnant (4 months) wife.”

Julie Tate contributed to this report.