The US-run prison in Bagram operates in the shadows, say rights activists.
His CIA jailers held the handgun and drill close to the prisoner to frighten him into giving up information.
Al-Nashiri, who US investigators believe is connected to the bombing of the US Navy destroyer Cole in 2000, was also subjected to a form of simulated drowning known as waterboarding, The Washington Post said.
The report, completed in 2004 by John Helgerson, the inspector-general, also says that a mock execution was staged in a room next to one suspect.
CIA officers fired a gun in the next room, leading the prisoner to believe that a second detainee had been killed, The New York Times said.
Details of the report were first published by Newsweek magazine on its website late on Friday.
A federal judge in New York has ordered a redacted version of the classified CIA report to be made public on Monday, in response to a lawsuit by the American Civil Liberties Union.
Lawyers for the justice department and the CIA have been scrutinising the long-concealed agency report since June to determine how much of it can be made public.
Al-Nashri was one of two CIA detainees whose interrogation sessions were videotaped, but the tapes were destroyed by CIA officers in 2005, the Times said.