The analysis by the American Civil Liberties Union, released today, looked at 44 deaths described in records obtained by the ACLU. Of those, the group characterised 21 as homicides, and said at least eight resulted from abusive techniques by military or intelligence officers, such as strangulation or "blunt force injuries", as noted in the autopsy reports.

The 44 deaths represent a partial group of the total number of prisoners who have died in US custody overseas; more than 100 have died of natural and violent causes.

In one case, the report said, a detainee died after being smothered during interrogation by military intelligence officers in November 2003. In another case cited by the report, a prisoner died of asphyxiation and blunt force injuries after he was left standing, shackled to the top of a door frame, with a gag in his mouth.

One Afghan civilian, believed by the ACLU to be Abdul Wahid, died from "multiple blunt force injuries" in 2003 at a base in Helmand province, Afghanistan, according to an autopsy report provided by the Defence Department.

Wahid, 28, was taken from his home by Afghan militia and accused of being a terrorist. The autopsy report said he died in American custody, although his father has blamed the militiamen.

The detailed list of prisoners whose deaths the report considered homicides includes two detainees who were beaten and died from "blunt force injuries" at the Bagram Airfield detention centre in Afghanistan, according to the autopsies.

Earlier this month, Private First Class Damien Corsetti, a military intelligence interrogator with the 519th MI Battalion at Fort Bragg, North Carolina, became the 15th soldier to face charges since those 2002 deaths.

Details about the detainee abuse and deaths have been released by the Pentagon as part of a Freedom of Information Act lawsuit filed by the ACLU. Many of the incidents have been made public before, and in a number of cases the soldiers and officers involved have been prosecuted and punished.

"The US military does not tolerate mistreatment of detainees," army spokesman Colonel Joseph Curtin said. "Past cases have been fully investigated. When there is credible evidence, commanders have the prerogative to prosecute."

To date, there have been more than 400 investigations of detainee abuse, and more than 230 military personnel have received a court-martial, non-judicial punishment or other administrative action.

"There is no question that US interrogations have resulted in deaths," ACLU executive director Anthony Romero said. "High-ranking officials who knew about the torture and sat on their hands and those who created and endorsed these policies must be held accountable."

The data includes detainees who were interrogated by military intelligence, Navy Seals and "Other Governmental Agency" personnel, which generally refers to the CIA.

ACLU documents: http://action.aclu.org/torturefoia/released/102405/