A FULL investigation should be launched into the “sickening” death of an inmate in a Scottish prison, politicians have said.

Allan Marshall, 30, died from a cardiac arrest after being dragged feet-first across the floor and restrained by multiple prison officers at HMP Edinburgh in March 2015.

A Fatal Accident Inquiry has now ruled his death was “entirely preventable”, while accusing prison officers of failing to tell the whole truth about what happened.

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Sheriff Gordon Liddle said: “Sometimes they appeared to be mutually and consistently dishonest.”

Mr Marshall was awaiting trial over a breach of the peace outside a nightclub in Hamilton when he suffered an episode of what is believed to have been Excited Delirium Syndrome.

He was restrained after being taken to the shower area of the prison’s Segregation and Reintegration Unit, where he was transferred after smashing up his cell and smearing it in excrement.

A violent struggle broke out, during which Mr Marshall - who had been displaying symptoms of mental illness for two days - sustained an “open facial injury” and prison guards were also hurt. Mr Marshall was later dragged “face down and feet-first by prison officers out into the corridor area”.

Cameras in the corridor showed five prison officers holding him down. One officer was seen to stamp on Mr Marshall.

After plastic handcuffs were applied, it then became clear Mr Marshall had stopped breathing. A “code blue” medical emergency alert was issued, but the recording was destroyed by the Scottish Prison Service.

In harrowing evidence, a prison nurse identified only as KQ said about 20 officers were standing shoulder to shoulder like a “penalty shoot-out” when she arrived.

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The sheriff’s report added: “She had to ask them to get out of the way. She asked what had happened and nobody answered – there was just silence.

“She described the prison officers as looking through her. She asked if an ambulance had been called and got no response from any of the prison officers.

“She described Mr Marshall as having injuries from head to toe. His tongue was enormous and hanging out of his mouth. He was pale and his ears were blue. She wondered if he had hanged himself.

“The skin was shaved off the top of his feet. His shoulder had what looked like pressure sores. He had a big gaping cut over his eye, which had been bleeding.

“There was dried blood on his face and blood in his eyelids and nose.”

Mr Marshall died four days later at Edinburgh Royal Infirmary. Experts said he had an underlying heart condition but the incident in HMP Edinburgh may have increased his risk of cardiac arrest.

Tory MSP Liam Kerr said it was a “truly awful case which leaves many questions needing to be answered”.

He added: “It is the duty of prison officers to ensure the wellbeing of inmates, yet alleged negligence has led to this man’s death. We need to find out exactly how this was able to occur in the first place, and put in measures to ensure it doesn’t happen again.”

Labour MSP Pauline McNeill called the details sickening, adding: “It is hard to believe this happened in a Scottish jail. I chaired the Justice Committee for six years and I have never read anything this.

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“It is extremely disturbing, in fact sickening, to read that the death of Alan Marshall but for the failures and actions by the hands of our own prison service could have been prevented.

“That this case is surrounded by serious suggestions of lies, deceit and cover up at the heart of the prison service demands forensic investigation.

“Absolutely nothing justifies the behaviour of those who were involved.

“If the Scottish Government are serious about true justice and a modern professional prison service no option must be ruled out in response, including dismissals. There must be accountability.”

LibDem MSP Liam McArthur added: “There can be no excuse for the errors which led to Mr Marshall’s brutal death.

“Prison staff operate in a highly pressured environment, but there is absolutely no room for violence of this kind in Scotland’s criminal justice system.

“This Fatal Accident Inquiry has exposed a horrifying incident and grievous failures that happened four years ago.

“Recommendations have now been made that could prevent the fatal outcomes in the future.

“But in between, years have gone by where there has been no public scrutiny, and no lessons learned.

“Why did it take so long for this appalling death to become public?”

A Scottish Government spokesman said: “Our thoughts and condolences are with the family and friends of Allan Marshall.

“We recognise the importance of providing a safe and secure environment for those in custody and we will continue to work with the Scottish Prison Service and other partners to ensure people in prison get the treatment they may need and frontline staff are properly supported.”

The Scottish Prison Service said it was considering the sheriff’s report and would respond in due course. It is understood some of the staff members involved are no longer with the service.