The disclosure was in response to a Freedom of Information Act lawsuit filed by the American Civil Liberties Union (ACLU).
The documents made public a series of memos detailing interrogation methods that President Barack Obama has labeled "torture" but the CIA refers to as "expanded interrogation" and has also been called "enhanced interrogation techniques." The documents also contain internal discussions of the legality of these methods.
In a document titled "Description of Physical Pressures," potential physical and psychological pressures are discussed to include a facial slap, use of diapers, "insects," and "mock burial."
"One possibility is to threaten to place stinging insects into the cramped confinement box with" the detainee "but instead place harmless insects," the document says.
It also says a "mock burial" would involve placing the prisoner in "a cramped confinement box that resembles a coffin. The box has hidden air holes to prevent suffocation."
In one heavily redacted communique sent out on August 12, 2002, the author discourages CIA employees from using "speculative language as to the legality of given activities" and from making "judgment calls as to their legality." The note concluded by saying "such language is not helpful."
Another CIA official wrote more bluntly in an email that the interrogation program was a "train (wreck) waiting to happen and I intend to get the hell off the train before it happens."
Much of the information contained in the documents has previously been made public, including during a Senate investigation in 2014.
According to one memo, even President George W. Bush was concerned about the interrogation practices. The memo dated June 7, 2006, says that during a meeting that same day, Bush's then Director of the Central Intelligence Agency, Porter Goss, had said that the President "was concerned about the image of a detainee, chained to the ceiling, clothed in a diaper and forced to go to the bathroom on themselves."
The memos also offer a robust defense of the interrogation tactics, with one official writing in March 2005: "We believe that intelligence acquired from these interrogations has been a key reason why al-Qa'ida has failed to launch a spectacular attack in the West since 11 September 2001."
One of the memoranda provides some guidelines for the techniques.
"CIA officers and other personnel acting on behalf of CIA may use only Permissible Interrogation Techniques," the memo says, adding that included waterboarding and forcing detainees to wear adult diapers for the purposes of "humiliation."
The memo says the techniques "do incorporate physical or psychological pressure beyond standard techniques" but require medical and psychological personnel to be onsite during all interrogations employing these techniques and that those personnel "shall suspend the interrogation if they determine that significant and prolonged physical or mental injury, pain, or suffering is likely to result if the interrogation is not suspended."
The document cache also includes an Inspector General's report pertaining to the rendition and detention of German citizen Khalid Al-Masri. The report determined that Masri was wrongfully detained for months, even after the agency realized that he was no justification to hold him. It attributes this in part to "failures of both legal and management oversight."
Another declassified report is an investigation into the death of the militant Gul Rahman in a detention facility in Afghanistan. The report details how he was subjected to constant music, sleep deprivation, stripped down to his diaper and placed in an "extremely cold" cell. Rahman was determined to have died of hypothermia while in detention.
"These newly declassified records add new detail to the public record of the CIA's torture program and underscore the cruelty of the methods the agency used in its secret, overseas black sites," Jameel Jaffer, ACLU deputy legal director, said in the ACLU's press release.