The family of a farmer abducted and murdered by the IRA say they believe the net is closing in on his killers.
It follows news that a fresh investigation into the Tom Oliver case has uncovered new DNA evidence, which investigators hope will lead to a prosecution.
Mr Oliver, an innocent farmer from the Cooley Peninsula in Co Louth, was abducted and shot by the IRA in July 1991.
The body of the father-of-seven was dumped across the border in Co Armagh.
His son Eugene, at the age of 13, went looking for his father after he failed to return from calving a cow and discovered his car in a field with the keys in the ignition.
Jon Boutcher, the former chief constable of Bedfordshire who heads Operation Kenova, is investigating a series of unsolved murders in Northern Ireland.
Speaking at the spot where Mr Oliver's car was found, the former police chief said they have recovered new DNA evidence that he hopes will "significantly assist" their investigation.
A family statement said: “The 30th anniversary brings with it mixed emotions. In those 30 years we have grieved in silence — without any meaningful investigation.
"There has been a catalogue of failed investigations which have been ineffective from their inception. We now have hope that the net is closing on those responsible for Tom’s murder.
"Operation Kenova has now confirmed that fresh evidence has come to light which includes fresh DNA evidence. This is coupled with a focused investigation with specific lines of enquiry — not just nationally, but internationally.
"After 30 years, there is now light at the end of a very dark tunnel. We today seek to call upon those with information to come forward and assist Jon Boutcher with his enquiries.”
Mr Boutcher’s team has been investigating the murder of Mr Oliver since April 2019.
"In that time, working with the garda, we've taken a significant number of new statements, and I'm pleased to say, using the techniques available to us today, we've recovered new DNA evidence that I am hoping will significantly assist us and this incredibly brave family in understanding what happened to Thomas that day," Mr Boucher said.