A fresh investigation is to be launched into allegations made in 2004 that British troops killed twenty Iraqi prisoners and tortured nine other detainees after a battle with insurgents.

The High Court has been hearing evidence in a judicial review case, brought by families of the alleged victims, and yesterday lawyers acting for the Defence Secretary conceded that there was a case for the new inquiry.

The Royal Military Police investigated the alleged mistreatment and killing of Iraqi detainees which, it was claimed, occurred in the aftermath of the so-called Battle of Danny Boy near Majar al-Kabir in southern Iraq. The military police concluded that there was no basis for the allegations.

Lawyers acting for the families of those who died and for the nine Iraqi detainees who claim they were tortured alleged that all 29 had been detained during the Battle of Danny Boy and that 20 had died in custody.

Martyn Day, of the solicitors Leigh Day & Co in London, and Phil Shiner, of Public Interest Lawyers in Birmingham, claimed that the mistreatment and killings took place at a British Army base at Camp Abu Naji, near Majar al-Kabir, on May 14 and 15, 2004. They produced witness statements, which included allegations that detainees had been executed. They also accused the MoD of failing to provide documents connected to the case.

When the military police investigated the claims, they said that they could find no evidence that any of the Iraqis who had been killed had died of injuries other than as a result of the fighting at the Danny Boy checkpoint.

They said that the bullet wounds were consistent with small arms and machinegun fire. A senior officer involved in the fighting dismissed as outrageous allegations that the 20 Iraqis had died after the battle in a British detention centre. Additional allegations that seven of the bodies showed signs of mutilation and torture were also rejected.

Bill Rammell, the Armed Forces Minister, said yesterday: “It is clear from the evidence that no one was murdered or ill treated by British Forces. It is also clear that British Forces did not mutilate corpses on the battlefield, and there is independent expert testimony to support this.

“However, these are serious allegations and we regret that we have failed to provide the court with timely and sufficient disclosure of information to enable them to determine the facts.

“Given these failings of disclosure, we have suggested to the court that a fresh investigation be undertaken into allegations of the murder of Iraqi detainees at Camp Abu Naji on the night of May 14-15, 2004, and specific allegations by five Iraq nationals of ill treatment.”

The judicial review is still under way and the MoD has not been told what form the new inquiry should take.

Times Recommends

• Times Charity Appeal: SolarAid
• Is it Black Monday all over again for Dubai?
• Behind the scenes at the biggest deal