Handguns, electric drills and mock executions were used by CIA agents to elicit information from terror suspects, US media have reported.
The reports contain details of a 2004 review by the CIA's inspector general that has been kept secret but is now due to be released next week.
Publication of the CIA report was ordered after a legal challenge by the American Civil Liberties Union.
The US has banned harsh interrogation methods, including death threats.
The gun and the drill were brought into an interrogation session of suspected USS Cole bomber and alleged al-Qaeda commander Rahim al-Nashiri, according to reports in the Washington Post, Newsweek magazine and AP news agency.
The CIA report says the drill was held near Saudi-born Mr Nashiri's head and repeatedly turned on and off, the reports said. The agents showed him the gun and tried to frighten him into thinking he would be shot.
In another case, a gun was fired in another room to lead a detainee to believe another suspect had been killed.
