A Limerick father has called for a review of a decision by the DPP not to prosecute the man he claims murdered his 19 year old son.

Jeffrey Hannon was beaten to death with an axe in 2007.

Twenty people have been arrested, but no one has ever been charged.

Two years ago a key witness came forward with information linking the chief suspect to the murder.

This led to the re-arrest of six people but the DPP says there is not sufficient evidence to proceed with a prosecution.

David Raleigh reports from Limerick.