The Scottish Prison Service has admitted that the death of a man in custody was unlawful – 10 years on from the fatality.

Allan Marshall, 30, was on remand at HMP Edinburgh in March 2015 when he was restrained face down by 17 prison officers. He died four days later.

His family has now received an apology from the prison service, Crown Office and Police Scotland after the Court of Session heard that the level of force went beyond what was necessary.

It is the first time that all three parties have publicly apologised, accepted it as an unlawful death and accepted that the state failed to adequately investigate.

Mr Marshall, from Carluke in South Lanarkshire, was on remand for unpaid fines and breach of the peace charges when he experienced a mental health crisis.

He was transferred to HMP Edinburgh’s segregation unit after prison officers said he had become agitated.

CCTV showed Mr Marshall, who had an underlying heart condition, being dragged and restrained by up to 17 prison officers – some of whom used their feet.

The court heard that there was “never any need” for force to be used on Mr Marshall and that he should have received medical attention instead.

It also heard that plastic cuffs were used and the “extent of force was plainly excessive and beyond what was necessary”.

The KC acting on behalf of Scottish ministers and the Scottish Prison Service said they acknowledge the “significance and the gravity of such a concession in respect of an individual who was in the custody of the state at the time of his death”

The Scottish Prison Service said it had “learned” from the incident and continually sought to improve how it supports staff and keeps people safe.

A spokesperson added: “We sincerely apologise for failings which resulted in the sad death of Mr Marshall and our thoughts and condolences remain with his family.”

Outside the Court of Session in Edinburgh, Mr Marshall’s aunt Sharon MacFadyen said the family had been waiting a decade for the admission.

“It doesn’t feel real, it’s still like we’re in a daze,” she said.

Jo Farrell, chief constable of Police Scotland, said: “The investigation following the death of Allan Marshall in 2015 fell below the standard required and for that I am sorry.

“On behalf of Police Scotland, I apologise to Allan’s family and place on record my condolences for their loss.”

The family’s lawyer, Barbara Bolton, said the Scottish Prison Service should have publicly apologised to the family long ago.

“Finally they have secured the admissions that they ought to have had,” she said.

“But instead they have had denial and they have been ignored and they have had to fight for this for 10 years.”

An unpublished Crown Office review seen by BBC Scotland in 2024 said a decision not to prosecute the prison officers, made two months after Mr Marshall’s death, was “incorrect”.

The Crown Office said it had undertaken “significant reforms” since Mr Marshall’s case and that bereaved families “can expect investigations to be pursued with the vigour and expertise they deserve”.