The men were surrounded by a mob and killed

The six Red Caps were killed in an Iraqi police station on 24 June last year after being surrounded by more than 400 protesting Iraqis.

Files on Sgt Simon Cullingworth and Sapper Luke Allsop, lost in March 2003, are also at the Central Criminal Court.

Defence Secretary Geoff Hoon's move has angered the men's families.

Reg Keys, whose son L/Cpl Thomas Keys was amongst the Red Caps killed, told BBC News Online his son had been "betrayed in life and now betrayed in death".

RMP TROOPS KILLED IN IRAQ Corporal Simon Miller, 21 Tyne and Wear Sergeant Simon Alexander Hamilton-Jewell, 41 from Chessington, Surrey Corporal Russell Aston, 30 Swadlincote, Derbyshire Corporal Paul Graham Long, 24 Colchester Lance-Corporal Benjamin John McGowan Hyde, 23 Northallerton, Yorks Lance-Corporal Thomas Richard Keys, 20 Bala, N Wales

"I'm incensed by it. Geoff Hoon had reassured me 12 months ago that they had the names [of the killers]. They've had 12 months to arrest them.

"Now they have an excellent excuse to wash their hands of it. The killers will never be found."

Mr Keys, from Llanuwchllyn near Bala in North Wales, said the handover of power to the Iraqis gave the MoD its excuse, but that the Iraqis would not make the investigation a priority. He said MP Elfyn Llwyd would now pursue the case in Parliament.

'Best prospect'

A spokesman for the MoD compared the process of handing over the investigation to the Iraqi court as similar to the UK procedure of police passing on files to the Crown Prosecution Service for charges to be considered.

The spokesman said the separate "board of inquiry" into how the incident happened would continue.

Mr Hoon said it was necessary to pass the files to the court, which was established by the Coalition Provisional Authority last year.

"The CCCI represents the best prospect of dealing with such cases in an expeditious and fair manner as Iraqi law has a bar to extraditing its own nationals to a foreign state, including the UK," he said in a written statement.

"If these cases are to be pursued through the CCCI then it is important that the concluding phases of the investigations are conducted under the court's direction, to ensure compliance with the rules and procedures of the court."

It has been reported that the soldiers men were under-equipped for their work, with as few as 20 bullets each.

Tony Hamilton-Jewell, whose brother Simon was the group's sergeant, said the government had timed the announcement to guarantee minimum coverage.

"It is just another wriggleout... they are just on one big cover-up.

"They want it to drag out as long as possible so it dims in people's minds."