A west Belfast man found guilty of murdering a prison officer, who died 11 days after a bomb exploded under his van, has been given a minimum jail term of 22 years.

Adrian Ismay, 52, died in hospital in 2016 after he was injured in the explosion near his home at Hillsborough Drive in east Belfast.

Christopher Robinson, 50, from Aspen Walk, had denied the murder.

In March, a judge said Robinson was "intimately and inextricably involved".

Robinson was also found guilty of possessing an improvised explosive device.

The non-jury trial heard that Robinson knew his victim from their time volunteering together for St John Ambulance.

Mr Justice McAlinden told Belfast Crown Court that Mr Ismay's murder had been "perpetrated in pursuance of a twisted republican terrorist ideology".

"The defendant played an important and integral role in planning and carrying out the terrorist operation which resulted in the death of Mr Ismay," he added.

Robinson was given a life sentence for the murder, but will be eligible to apply for release under licence after 22 years, the judge said.

In 2016, a dissident republican group widely referred to as the New IRA had claimed it had carried out the attack on Mr Ismay.

Robinson had denied he was an active member of the New IRA.

Before determining the appropriate minimum sentence, the judge highlighted the victim impact statements the court had received from Mr Ismay's widow and his daughters.

He said the "heart-wrenching statements managed with dignified reserve to convey how deeply they all loved Mr Ismay and how intensely he adored them".

"Only the hardest and coldest heart of stone would not be deeply affected reading them and anyone of normal sensitivity could not but readily perceive how each of the authors of those statement and those referred to therein have been utterly devastated by this murder and their lives have been altered irretrievably," he added.

"They will endure the cruel impact of the tragic loss of Mr Ismay for the rest of their lives."

Mr Justice McAlinden said "the loss of Mr Ismay's life cannot be measured by the length of a minimum term prison sentence".

The judge also paid tribute to the "unstinting community service" which Mr Ismay had engaged in.

"He lived to train, help and guide others," he said.

"He was a decent, warm, generous and loving human being and our society is the poorer for his loss.

"If only there were more like him.

"His legacy is his example of unstinting and enthusiastic community engagement; reaching out to and engaging with all, irrespective of background."

Mr Ismay had just left his home and was driving along Hillsborough Drive at about 07:00 GMT on 4 March 2016 when the bomb planted under his van detonated.

In spite of appearing to make a good recovery from shrapnel injuries, he died 11 days later.

In March, a judge said Robinson was linked to the murder by evidence including his DNA on a Poppy Appeal sticker that was removed from a vehicle containing traces of Semtex.

He also said CCTV footage clearly showed the vehicle - which was registered to Robinson's sister-in-law - outside Mr Ismay's home when the bomb was planted.

The judge added that CCTV at the workplace of Robinson's brother had been disabled several times by his sibling so he could not be filmed visiting him.

Robinson's high level of online interest into the treatment of dissident republican prisoners - as well as internet searches about militant republican activity - was further evidence cited by the judge.

Det Supt Richard Campbell, from the Police Service of Northern Ireland (PSNI), said Robinson's sentence was "deserving" for the "brutal and horrific killing" of Mr Ismay.

"He knew Mr Ismay, as they volunteered together in the local community, but callously betrayed him by his involvement in planting an explosive device under the prison officer's van just because of how he earned his living," he said.

"Adrian Ismay, who was a husband and a father, was a hard-working man who had left his home that Friday morning to do his job and to keep people safe," he added.

He said his thoughts were with Mr Ismay's family who "will be reliving the horror of what happened more than four and a half years ago".

"They face their own life sentence as they will never see Mr Ismay again. Their lives have been shattered," he said.

He added that while sentencing would not "take away the pain and heartache felt each day by his family" he hoped it would "bring them some comfort in knowing that his killer is behind bars".