An independent inquiry has concluded British soldiers serving in Iraq beat a civilian to death in what it called an act of unjustified and brutal violence.
Chairman Sir William Gage said the assault on Baha Mousa and nine other detainees in the city of Basra left a very great stain on Britain's armed forces.
Mr Mousa died in army custody in Basra in 2003. He had 93 external wounds, as well as internal injuries.
Prime Minister David Cameron said such an incident should never happen again.
Sir William blamed ''corporate failure'' at the Ministry of Defence for the use of banned interrogation methods in Iraq.
''It was avoidable and preventable, and there can be no excuses. There is no place in our armed forces for the mistreatment of detainees,'' said Defence Secretary Liam Fox.
The BBC reports Mr Mousa was arrested on 14 September 2003 by members of the 1st Battalion The Queen's Lancashire Regiment and died two days afterwards.
The inquiry concluded that the death was caused by a combination of his weakened physical state and a final bout of abuse.
He was hooded for almost 24 of the 36 hours he spent in detention.