Up to 20 Iraqi civilians may have been executed by British troops in southern Iraq, it has been claimed.
Lawyers published a dossier of evidence from men taken captive after a gun battle near the southern Iraqi town of Majat-al-Kabir in May 2004, which also suggested prisoners were tortured and mutilated by UK military.
The allegations were first reported within weeks of the incident, known as the Battle of Danny Boy after a checkpoint where it took place, but lawyers for five Iraqis have issued detailed witness statements, photographs of corpses and death certificates of the men who died.
The claims - which the Ministry of Defence (MoD) strongly denies - are among the most serious yet levelled against British soldiers who served in Iraq.
Solicitor Phil Shiner said of the dossier: "We would be very surprised if it did not shock the nation."
However, a spokesman for the BBC's Panorama programme, which has spent a year examining the claims, said the evidence did not prove Iraqis had died at the hands of British captors, but that prisoners may have been "mistreated".
Lawyers Mr Shiner and Martyn Day suggested that prisoners captured after the three-hour gun battle may have been taken to a British base at Abu Naji and killed.
Detailed witness statements from the five men - Hussein Jabbari Ali, Hussain Fadhil Abass, Atiyah Sayid Abdelreza, Madhi Jassim Abdullah and Ahmad Jabber Ahmood - described what they heard while in detention, when they were cuffed and forced to wear blacked-out goggles.
The statements described how they heard other men screaming, moaning in pain and choking and also the sound of gunfire.
The lawyers are bringing a damages claim in the UK courts, and say the five witnesses are labourers who have lived all their lives in Majar and had "absolutely nothing" to do with the insurgent Mehdi army, which engaged British troops at the Battle of Danny Boy.
