A court martial has cleared two UK soldiers of failing to ensure their men did not abuse Iraqi civilians in Basra.
Baha Mousa died in custody after being arrested in Basra
Maj Michael Peebles and Warrant Officer Mark Davies had denied charges of negligently performing their duties.
In all, six soldiers were acquitted at the hearing in Bulford, Wiltshire. A seventh soldier had previously admitted one charge of inhumane treatment.
The allegations arose after the death of an Iraqi prisoner, Baha Mousa, in British custody during September 2003.
Cpl Donald Payne, who admitted treating Iraqis inhumanely, is the only soldier to have been convicted at the end of the six-month hearing. He is awaiting sentencing.
In a statement, the Ministry of Defence pledged that if "lessons need to be learned, we shall do so".
"Today's judgement has been an important one and we will need time to consider fully the serious implications," the statement said.
The MoD added that they needed to "maintain both operational effectiveness and the public's trust and confidence".
Senior soldiers and defence lawyers hit out at the court martial system following Tuesday's acquittals.
Gilbert Blades, solicitor for Maj Peebles, said the case "exposed the weaknesses and gaps" in the system.
"If charges are brought, the case should be capable of standing up to scrutiny by the court," he said.
But Mr Blades claimed that none of the soldiers who faced court martial should have been charged - with the exception of Cpl Payne.
"[Prosecutors] have come unstuck every time they have dealt with this type of case," he added.
The seven soldiers were all from the Queen's Lancashire Regiment.
Col David Black, of the QLR's Regimental Council, said that British servicemen needed to operate without being "inhibited by the fear of such actions by over zealous and remote officialdom".
Col Black labelled the trial an "extraordinary ordeal" for the soldiers, their families and the regiment as a whole.
"We are relieved that today, after three and a half years, there is a sense of closure."
But Phil Shiner, who represented the Iraqis at the court martial, labelled the outcome a "travesty".
"It gives the victims nothing. It raises more questions than it answers."
Among those charged but later acquitted was Col Jorge Mendonca - the most senior UK soldier in recent history to face a court martial.
The accusations against the Col Mendonca and his men stemmed from an Army raid on a Basra hotel in September 2003, where they found weapons and suspected bomb-making equipment.
The soldiers detained a number of Iraqis and took them to the Darul Dhyafa military base for questioning.
The prosecution said some of the Iraqi suspects were hooded, beaten and deprived of sleep.
Baha Mousa, 26, was among the group of detainees. After his death, his body was found to have 93 separate injuries.