New York - The US military knew troops had abused Iraqi prisoners for months before graphic, humiliating photographs surfaced last week, a journalist who read a US army report said on Sunday.
"There were three investigations, each by a major general of the army," Seymour Hersh told CNN's Late Edition.
"Clearly somebody at a higher level understood there were generic problems."
Hersh published his article in The New Yorker, based on an army investigation by Major General Antonio Taguba, which was not intended for public release.
"Specifically, Taguba found that between October and December of 2003 there were numerous instances of 'sadistic, blatant and wanton criminal abuses' at Abu Ghraib," he said. Abu Ghraib is a US-run prison in Baghdad.
Hersh said the abuses went far beyond those portrayed in the widely broadcast photographs of sexual abuse, nudity and humiliation that have angered the Arab world. They were first shown on CBS television's 60 Minutes II.
The army investigation resulted in discipline and courts-martial for the troops involved.
However, the 53-page report also made it clear that the troops would not have attempted to break down prisoners in this way, Hersh said, unless higher-ups or intelligence agents wanted them to soften the prisoners up for later interrogation, or, euphemistically, to "set the conditions" for the session.
Taguba himself wrote: "I find that personnel assigned to the 372nd (Military Police) Company, 800th MP Brigade were directed to change facility procedures to set the conditions for (Military Intelligence) interrogations.
Army intelligence officers, CIA agents and private contractors "actively requested that MP guards set physical and mental conditions for favourable interrogation of witnesses", Taguba wrote.
Hersh quoted a list of abuses directly from the investigation: "Breaking chemical lights and pouring the phosphoric liquid on detainees; pouring cold water on naked detainees; beating detainees with a broom handle and a chair; threatening male detainees with rape; allowing a military police guard to stitch the wound of a detainee who was injured after being slammed against the wall in his cell; sodomising a detainee with a chemical light and perhaps a broomstick; and using military working dogs to frighten and intimidate detainees with threats of attack and, in one instance, actually biting a detainee."