The head of the British Army has ordered an inquiry into the abuse of Iraqi prisoners by three British soldiers near Basra in May 2003.
Larkin pleaded guilty to one charge of assault
General Sir Michael Jackson, who has apologised to the people of Iraq, said lessons needed to be learned.
His announcement was welcomed by shadow defence secretary Nicholas Soames.
Defence Secretary Geoff Hoon said he was "profoundly disturbed" by the case, which saw three men jailed by a military court martial in Germany.
Mr Soames told BBC Radio 4's Today programme that an inquiry "needs to cover a very substantial amount of ground in order that we can minimise the possibility of these things going wrong".
He said soldiers appeared to have been given inadequate orders, blaming a lack of preparation for post-war Iraq and lack of resources.
IRAQ ABUSE SENTENCES
Cooley found guilty of disgraceful conduct of a cruel kind after he drove a forklift truck with a bound Iraqi suspended from the prongs
Cooley also convicted of simulating a punch in a picture
Larkin pleaded guilty to assault after he was pictured standing on top of an Iraqi
Kenyon found guilty of failing to report that a soldier under his command had caused an Iraqi detainee to be raised on the forks of a forklift truck
Kenyon also convicted of aiding and abetting Larkin to assault a prisoner
Kenyon found guilty of failing to report that soldiers under his command forced two naked prisoners to simulate sex
Kenyon found not guilty of two charges of aiding and abetting unknown persons to force the detainees to simulate a sex act
Lawyers for L/Cpl Mark Cooley, Cpl Daniel Kenyon and L/Cpl Darren Larkin said the men, sentenced at a trial in Osnabrueck, felt they had been made "scapegoats" for the abuse.
The men were dismissed from the Army in disgrace. Cooley, 25, was jailed for two years while Kenyon, 33, received an 18-month sentence and Larkin, 30, 140 days.
General Sir Michael said he wanted to "place on record how appalled and disappointed I was when I first saw those photographs at the outset of the trial".
But he said the case had to be put in the context of the actions of thousands of British servicemen and women "continuing to do a most difficult job in Iraq".
General Sir Michael said four other known cases involving allegations of deliberate abuse had been, or may be, referred to the authorities, but did not comment further on the cases.
The fate of the soldiers, from the 1st Battalion The Royal Regiment of Fusiliers, was decided by Judge Advocate Michael Hunter and a panel of seven senior officers.
After the sentences were announced, one of the soldiers' lawyers said his client felt that "a significant number of other soldiers, including many senior to him, some of whom have been promoted, were involved in the mistreatment of Iraqis that day".
Defence Secretary Geoff Hoon said the Army had shown it took such allegations seriously.
He said: "The Army set high standards and demand that they are met. The recent court martial has demonstrated that those who fail to meet those standards are called to account."
Sir Mike said he was appalled by the abuse pictures
The abuse came to light when photographs taken by a fourth soldier, Gary Bartlam, were left in a Staffordshire shop to be developed.
His family have claimed he has been made a scapegoat. In an interview with the Today programme, his mother Maggie said an injury had meant her son had missed out on refresher training on the Geneva Convention before being deployed to Iraq.
"When all the other soldiers were in the classroom, Gary was lying in hospital," she said.
She said her son had called her from Iraq detailing some of the things the soldiers had allegedly been ordered to do, such as forcing looters to run with boxes of milk powder to tire them out.
"Gary was there to follow orders, and that's what he did," she said.
In their defence, the soldiers claimed abuse stemmed from an unlawful mission which took place at the aid camp to capture and deter looters.
The mission, codenamed Operation Ali Baba, was ordered by the camp's commanding officer, Major Dan Taylor, who told his troops looters should be "worked hard".
Prosecutors said the operation was in breach of the Geneva Convention.
General Sir Michael said that, although no criminal action had been taken against Maj Taylor, "administrative action" remained a possibility.
In a separate court martial last year, Bartlam admitted taking photographs of Iraqis simulating sex acts, sentenced to 18 months in a youth detention centre and disgracefully discharged from the Army.