A UK public inquiry will be held into the death of Iraqi civilian Baha Mousa, the government has announced.
Mr Mousa died while in British army detention after being taken into custody in Basra in September 2003.
Defence Secretary Des Browne told MPs an inquiry "will reassure the public that we are leaving no stone unturned in investigating his tragic death".
Lawyers for Mr Mousa's relatives said other alleged cases of manslaughter and torture should also be examined.
Mr Mousa, a hotel receptionist, died after being taken into custody.
His post-mortem examination showed he suffered asphyxiation and had some 93 injuries to his body.
Mr Browne, announcing the inquiry, said: "A public inquiry into the death of Baha Mousa is the right thing to do.
"The Army has nothing to hide in this respect and is keen to learn all the lessons it can from this terrible incident."
General Sir Richard Dannatt's views on the inquiry
Mr Browne also issued a Written Ministerial Statement to Parliament, saying that the terms of reference had yet to be set and the Army and Ministry of Defence would co-operate.
He added: "Overall, the conduct of tens of thousands of our people in Iraq has been exemplary; it is a tiny number who have caused a stain on the reputation of the British army.
"But that does not mean we can allow these events to pass without looking into them thoroughly."
Chief of the General Staff, General Sir Richard Dannatt said a court martial in 2007, as well as the Aitken Report into training this year, had "gone some way to shed light on this disgraceful incident".
This was not a case of misjudgement in the heat of battle, or in the heat of the moment. There can be no excuse
Gen Sir Richard Dannatt
Cpl Donald Payne was jailed for a year in 2007 after pleading guilty to inhumanely treating civilian detainees in Basra in 2003.
Six other soldiers were cleared of the alleged abuse of the detainees, who included Mr Mousa.
"The army knows that Mr Baha Mousa should have been treated properly and lawfully but he was not," Gen Dannatt said.
"This was not a case of misjudgement in the heat of battle, or in the heat of the moment. There can be no excuse."
He was asked on BBC Radio 4's PM programme why it was acceptable to have a public inquiry into Mr Mousa's death, but not one into the reasons for the 2003 Iraq War itself.
"When this operation is over and the British forces are withdrawn from Iraq, if there is an appetite to have an inquiry as to whether we should or should not have gone into Iraq, that is the right time to do it," he replied.
"What we are talking about here, focussed much more narrowly, but very importantly, are to ask questions about our conduct during those operations.
"That's a very separate issue from looking at whether we should've got involved in the operation in the first place."
Solicitor Phil Shiner, who represents Mr Mousa's family and other Iraqis said to have been mistreated, said a broad inquiry into the British army's detention policy was necessary.
"This would need to get to the bottom of how it came about that the five techniques banned in 1972 - hooding, stressing, food and water deprivation, sleep deprivation and noise - were reintroduced as apparently standard operating procedure for all Battle Groups," he said.
The announcement followed a Law Lords ruling - resulting from a legal aid-funded appeal case - that the UK's Human Rights Act applied to Mr Mousa because he had been detained by British forces.
David Keegan, from the Legal Services Commission, which oversees the legal aid system, said the public inquiry would allow Mr Mousa's family to see allegations surrounding his death "fairly and independently investigated".
He added: "This has been made possible as a result of legal aid funding for cases heard by the House of Lords."
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