But Phil Shiner, of Public Interest Lawyers, which has represented Iraqi civilians, dismissed the report as a "whitewash'" and said there was clear evidence that abuse had been "rife."
"What is important to understand is that the High Court will shortly have to decide whether to hold an independent and public inquiry into the UK's detention policy in Iraq,'" he said.
Report 'rightly critical'
Amnesty International, a human rights group, also called for a fully independent investigation after the report was published.
-Death of Nadhem Abdullah in May 2003.
A court-martial dismissed murder charges against seven British soldiers.
-Drowning of Saeed Shabram in May 2003. No charges were filed against three soldiers investigated.
-Abuse of Iraqi looters detained in May 2003. A court-martial found four soldiers guilty of various charges.
-Beating of Iraqi youths by British soldiers during a riot in April 2004. No disciplinary action was taken.
Richard Dannatt, the head of Britain's army, said: "This report is rightly critical of our performance in a number of areas and it catalogues the significant number of steps we have already taken toward ensuring that such behaviour is not repeated.'"
One of the cases covered by the inquiry included Baha Mousa, an Iraqi hotel receptionist, who died while being held by British forces in south Iraq, and Ahmed Jabber Kareem, a 16-year-old, who drowned after allegedly being forced to swim across the Shatt al-Arab River.
Mousa died while being restrained by soldiers after trying to escape custody.
A pathologist later told a military court that he died from asphyxia while being held in a stress position.
Six of the seven soldiers charged in relation to Mousa's death were cleared.
The seventh soldier, corporol Donald Payne, pleaded guilty to inhumanely treating Iraqi civilians in the southern Iraqi city of Basra in 2003.
Payne, Britain's first convicted war criminal, was sentenced to a year in prison and dismissed from the army.
Four service members were acquitted in Kareem's death and Mousa's case is still subject to further investigation.
The court-martial related to the Mousa case revealed "confusion" over the treatment of detainees, with senior officers apparently unaware that the "hooding'" of prisoners and sleep deprivation were banned under the Geneva Conventions and British law.
"The army condemns the sort of behaviour that has been exemplified in the cases of abuse with which this report is concerned,'" Aitken's 37-page investigation concludes.
However, the report went on: "There is no evidence of fundamental flaws in the army's approach to preparing for or conducting operations: we remain the envy of our allies for the professionalism of our conduct."
The inquiry's findings sparked an angry response from Mousa's father, who said it underplayed the role of the army's senior officers.
"As a senior officer in the Iraqi army, I am clear that these terrible actions could not have taken place without support from senior officers within the British army, Daoud Mousa said.
"I do not accept this report for a second."
Colonel Jorge Mendonca, who was cleared at a court martial last year of negligence in relation to Mousa's death and other abuse cases, said that the failures identified were a result of there being too few troops on the ground.
"None of that is addressed in the report, which I find deeply distressing," Mendonca, who later resigned from the army, said.
"If you send a small group of soldiers into a difficult situation, it seems to be pretty rich to then expect everything to go swimmingly and then blame a few commanders on the ground when things go wrong."
The report said the army should find better ways to entrench its core values, its standards of behaviour and discipline in its soldiers.
It also criticised the army for taking as long as three years to court martial soldiers involved in cases.