A New York-based human rights group has challenged America's treatment of 11 al-Qaeda suspects it is thought to be holding outside the US.
The suspects are thought to held outside the US
Human Rights Watch said prisoners were being denied access to the Red Cross and protection under international law, and it suggested torture had been used.
A spokesman compared their treatment to the 'dirty wars' of Latin America when people 'disappeared' while in custody.
A spokesman for the CIA declined to comment on the report.
Key al-Qaeda figures like Khalid Sheikh Mohammed, the suspected planner of the 11 September 2001 attacks, are among those being held as part of the US-led "war on terror".
Human Rights Watch, which based its 46-page report largely on news reports, acknowledged the need to bring terror suspects to justice but questioned the legality of the detainees' treatment.
The BBC's Jeremy Cooke reports from New York that the well-respected group has delivered a damning indictment.
HRW highlights a number of areas in which the US appears to be violating international legal standards:
- International treaties ratified by the US prohibit holding prisoners incommunicado and in secret locations
The Geneva Conventions require that the International Committee of the Red Cross has access to all detainees and that information on them be provided to their relatives
Under international human rights law, detainees must be held in recognised places of detention and be able to communicate with lawyers and family members
Reed Brody, special counsel with Human Rights Watch, said that "those guilty of serious crimes must be brought to justice before fair trials".
However, if the US chooses to ignore international law, "it abandons its ideals and international obligations and becomes a lesser nation", he added.
"'Disappearances' were a trademark abuse of Latin American military dictatorships in their 'dirty war' on alleged subversion," he said.
"Now they have become a United States tactic in its conflict with al-Qaeda."
Also on the list issued by HRW are Abu Zubaydah - said to have been an aide to Osama Bin Laden - as well as suspected would-be 9/11 hijacker Ramzi Binalshibh and Hambali, an alleged al-Qaeda ally in South-east Asia.
The report refers to news reports quoting unidentified government
sources acknowledging the torture or mistreatment of detainees.