THIS is the chilling moment two prisoners smirk before battering a fellow inmate to death in his cell.

Ashirie Smith, 19, and Thierry Robinson, 21, launched the brutal 37-second attack at HMP Fosse Way in Leicestershire, on August 20 last year.

Smith stomped on 31-year-old Mahir Abdulrahman’s head and neck in the savage assault.

A female prison officer found the victim, who had been serving time for sex offences, unresponsive inside his cell with horrific injuries.

Paramedics pronounced Abdulrahman dead at the scene at 7.45am, within an hour of the attack.

His cause of death was recorded as a sub arachnoid basal haemorrhage – bleeding to an area of the brain.

A court heard the prisoner had been subjected to taunts by Smith and Robinson for weeks before the fatal attack.

One altercation resulted with Abdulrahman throwing a hot kettle at them.

Smith carried out his brutal beating the following day, after a prison officer unlocked his cell door and continued on their rounds.

CCTV captured the moment a topless Smith, and dressing-gown wearing Robinson entered Abdulrahman’s cell before walking out around 37 seconds later.

Smith then re-entered and left the cell gain shortly after the assault.

The inmate had been serving time for firearms offences after police found a weapon under his mattress.

He was found guilty of murder and was jailed for life to serve a minimum of 17-and-a-half years at Leicester Crown Court on Thursday.

Robinson was found not guilty of murder but found guilty of manslaughter and was sentenced to 11 years imprisonment.

A third defendant Shaan Karim, 38, was found not guilty of murder and not guilty of manslaughter.

The court heard earlier that Mr. Karim had confessed to his mother over the phone that Robinson and Smith had attacked Abdulrahman, and admitted that he “could have done something” to intervene but chose not to.

He told her Abdulrahman’s 35-week prison sentence for a sexual offence had led to other inmates “terrorising him for days”, the court heard.

The court was also told Abdulrahman had asked a prison officer the day before he died if he could move cells because he did not feel safe.

Detective Inspector Mark Parish, from the East Midlands Special Operations Unit, stated: “The injuries Mahir Abdulrahman sustained indicated a severe, prolonged assault that tragically resulted in his death.”

“Due to the diligent efforts of the investigation team, Smith and Robinson have been found guilty in court and must now be held accountable for their actions,” he added.

Serco Prison Director Wyn Jones said: “Any death in prison is a tragedy but the murder of Mr Abdulrahman was a heinous act.

“My thoughts remain with his family and those affected by his untimely death.

“Since the tragedy, our focus has been to bring those responsible to justice by working with the police to secure a conviction.

“I hope the verdicts will bring closure for his family.”

Wyn Jones, Serco prison director, said: “Any death in prison is a tragedy but the murder of Mr Abdulrahman was a heinous act. My thoughts remain with his family and those affected by his untimely death.”