US military investigators say they have found evidence of degrading and abusive treatment by interrogators at the Guantanamo Bay prison camp in Cuba.
There have been calls for the camp to close
The general in charge of the inquiry, Randall Schmidt, said one key suspect was forced to perform dog tricks and dress up in women's underwear.
The report found three cases when army doctrine had been violated.
But the majority of the techniques observed had been authorised by the Pentagon, the report concluded.
The inquiry was launched after the FBI expressed concern about the treatment of prisoners at the camp.
The report, released at a Senate committee hearing, mentioned multiple instances of abuse at the prison.
However, it added that there were no cases of torture or inhumane treatment.
Interrogators violated regulations when:
- A female touched detainees inappropriately and smeared them with a substance described as menstrual blood, but which was fake blood
- Interrogators threatened to go after a detainee's family
- Duct tape was used to bind the head and mouth of a detainee chanting verses of the Koran
The report also found that:
- Military staff impersonated FBI and state department interrogators
- A detainee was chained to the floor in the foetal position
- Cold, heat, loud music and sleep deprivation were used on detainees.
The report said many techniques used, including those during the interrogation of the key suspect, were permitted.
The inquiry admonished the camp commander at the time for failing to oversee the interrogation.
But the Southern Command, which runs the base, said Maj Gen Geoffrey Miller had committed no violations.
Maj Gen Miller, who took over at the prison in 2002, has been criticised by human rights groups for his methods.
He has since been involved with overseeing prisoners in Iraq and is currently in a position at the Pentagon unrelated to detainees.
Cases of abuse at the camp have prompted criticism from human rights groups and senior US politicians, some of whom have called for it to be closed.
US military officials say disciplinary or administrative action has been taken in all 10 cases of misconduct documented since prisoners were first brought to Guantanamo in January 2002.
Michigan Senator Carl Levin, the top Democrat on the Senate Armed Services Committee, said the report showed there were more than a few isolated cases of abuse.
"It is clear from the report that detainee mistreatment was not simply the product of a few rogue military police in a night shift," he said.