The warders suffered 'severe psychological injuries'

The call comes a day after six warders won over £1m in compensation for witnessing the aftermath of the attack.

Inmate Jason Ricketts killed and mutilated his cellmate Colin Bloomfield in Cardiff prison in 2000.

The warders' solicitor, Frank Rogers, said there were mistakes made in placing Ricketts in a shared cell.

Mr Rogers told BBC News: "This man had been diagnosed as suffering a permanently incurable mental illness and yet he was left in prison and put in a shared cell.

"There is a broader issue of how the prison service deals with mentally disordered offenders who are known to be violent."

He said the scene the six men - Darren Godbear, 44, Nigel Thomas, 47, Michael Wakeham, 46, Gerald Williams, 58, Paul Evans, 38, and Alan Hunt, 42 - witnessed was on of "gothic horror", beyond the experience of any prison officer.

Colin Bloomfield was strangled as he lay on a bunk bed

Ricketts had rung a buzzer and said he had killed his cellmate. Officers discovered Mr Bloomfield's body cut open, with organs mutilated, and the cell covered in blood.

A convicted burglar, Ricketts, from Caerphilly, who was 29 at the time, had crafted a plastic spoon with a razor blade embedded in it and sharpened the handle of a toothbrush.

It transpired that he strangled Colin Bloomfield, 35, from Newport - a married paint-sprayer serving six months for an offence which cannot be published for legal reasons - before the attack.

Ricketts pleaded guilty to manslaughter on the grounds of diminished responsibility, claiming a man in white in the corner of his cell told him to do it. He was sent to Ashworth secure psychiatric unit for an unlimited time.

They were left to strip search this man and were then left - which I think was a callous disregard to their well-being - to finish their shifts for the rest of the night in blood-soaked uniforms

Solicitor Frank Rogers

Mr Rogers said the case had previously been referred to as a "Hannibal Lecter-style killing" and said the officers were exposed to a scene of "absolute horror".

"They were left to strip search this man and they were then left - which I think was a callous disregard to their well-being - to finish their shifts for the rest of the night in blood-soaked uniforms," he added

The warders involved are said to be still receiving medical treatment. Three of them still work at Cardiff jail but have limited contact with inmates.

On Wednesday, the Home Office agreed to the compensation after a hearing with High Court judge Mr Justice Field.

Nigel Cooksley QC, representing the officers, said: "On the night of the killing warder Nigel Thomas attended Ricketts' cell. When he saw Bloomfield he called for assistance and the five others came.

"They did not know what they were going to see and went in tentatively with their staves drawn. What they saw caused them all psychological injuries."

"One of them was obliged to attempt resuscitation on Bloomfield despite his obvious death," he added.

Ricketts was serving a sentence in Cardiff for burglary

Mr Rogers said that the six years it had taken for the matter to be resolved had seriously exacerbated their mental condition.

"I think it is time that not only is there an inquiry into the facts of this case but there is an inquiry into the whole issue of how the prison service and society deals with mentally disordered offenders who are dumped in the prison service," he added.

"It is not equipped to deal with people such as Ricketts, who had a permanently incurable mental illness and was known to have a violent propensity.

"These man should be in specialist hospitals where the resources and treatment skills are designed to deal with them."

Speaking on BBC Radio Wales, former Chief Inspector of prisons Lord David Ramsbotham said: "The whole business of the way the Prison Service sets about coping for people with these sort of problems really does need bringing out into the open."