The family of a prison officer who was murdered by the IRA 40 years ago say they have been given new hope after gardaí told them that they are following new lines of enquiry in the case.

Austin Stack, son of former Portlaoise prison officer Brian Stack, met with senior gardaí today in Dublin.

Speaking after the meeting, Mr Stack said gardaí told the family that the file on the case - which was with the DPP - is now being sent back to gardaí for further investigation.

He said gardaí told the family today there were now significant lines of enquiry that they were following, and the family will meet gardaí again in August for a progress report.

Mr Stack described the meeting as "upbeat" and said it had given the family new hope that it may lead to a conviction.

Brian Stack died 18 months after he was shot in the neck as he left a boxing match in Dublin in 1983.

The Provisional IRA later claimed responsibility for the shooting, but no one has ever been brought to justice.

Austin Stack has been involved in a long campaign to try get justice for what happened to his father.

In 2019 the family received an apology from Garda Commissioner Drew Harris in relation to the handling of the investigation into the murder.

A file was then sent to the DPP.

Mr Stack appealed to anyone who has information to come forward.

"We would ask anyone with any information that may assist the gardaí to come forward. Any little piece of information can add into something they already have.

"Last Friday it was 40 years since the shooting and we're still quite hopeful. I'm a lot happier than before I went into the meeting. It gives us renewed hope."