The report is based on interviews conducted in Libya with 14 former detainees, most of whom belonged to an armed Islamist group that had worked to overthrow Gaddafi for 20 years. Many members of the group, the Libyan Islamic Fighting Group (LIFG), joined the NATO-backed anti-Gaddafi rebels in the 2011 conflict. Some of those who were rendered and allegedly tortured in US custody now hold key leadership and political positions in the country.

“Not only did the US deliver Gaddafi his enemies on a silver platter but it seems the CIA tortured many of them first,” said Laura Pitter, counterterrorism advisor at Human Rights Watch and author of the report.

“The scope of Bush administration abuse appears far broader than previously acknowledged and underscores the importance of opening up a full-scale inquiry into what happened.”

The report is also based on documents – some of which are being made public for the first time – that Human Rights Watch found abandoned, on September 3, 2011, in the offices of former Libyan intelligence chief Musa Kusa after Tripoli fell to rebel forces.

The interviews and documents establish that, following the September 11, 2001 attacks, the US, with aid from the United Kingdom (UK) and countries in the Middle East, Africa, and Asia, arrested and held without charge a number of LIFG members living outside Libya, and eventually rendered them to the Libyan government.

“The involvement of many countries in the abuse of Gaddafi’s enemies suggests that the tentacles of the US detention and interrogation program reached far beyond what was previously known,” Pitter said. “The US and other governments that assisted in detainee abuse should offer a full accounting of their role.”

The report also describes serious abuses that five of the former LIFG members said they experienced at two US-run detention facilities in Afghanistan, most likely operated by the CIA. They include new allegations of waterboarding and other water torture. The details are consistent with the few other first-hand accounts about the same US-run facilities.

According to the report, the Libyan detainee accounts had previously gone largely undocumented because most of those returned to Libya were locked up in Libyan prisons until last year, when Libya’s civil unrest led to their release. And the US government has been unwilling to make public the details about its secret CIA detention facilities. The accounts of former detainees, the CIA documents found in Libya, and some declassified US government memos have shed new light on US detention practices under the Bush administration but also highlighted the vast amount of information that still remains secret, HRW said.

Despite overwhelming evidence of numerous and systematic abuses of detainees in US custody since the September 11 attacks, the US has yet to hold a single senior official accountable, according to HRW.

Since the fall of the Gaddafi government, US diplomats and members of Congress have met with some of the former CIA prisoners now in Libya, and the US has supported efforts by the Libyan government and civil society to overcome the legacy of their country’s authoritarian past. Human Rights Watch urged the US government to acknowledge its own past role in abuses and in helping Gaddafi round up his exiled opponents, to provide redress to the victims, and to prosecute those responsible for their alleged torture in US custody.