The remote Bragan Bog is not typically a hive of activity.

The lonely spot just a couple of miles across the border in Co Monaghan is usually the preserve of farmers but on Monday it witnessed a steady stream of activity, from diggers pulling up peat, to journalists from across Ireland navigating the tricky terrain.

This desolate landscape is believed to have witnessed the final moments of Co Tyrone teenager Columba McVeigh’s life after he was abducted from Dublin by the IRA.

The 19-year-old had just three weeks previously started a new life in the Irish capital.

On November 1, 1975 he was transported back up north, but instead of arriving to the warmth of his mother’s house in Donaghmore and embrace of his family, he was taken by terrorists to the cold, brutal landscape of Bragan bog where it is believed he was murdered and secretly buried.

Only his killers will know whether the teenager was aware he had been travelling north and latterly on a cross-border road before ending up on a narrow country road, and then a long bumpy lane way up a steep hill to the bog.

Some 43 years have passed, there have been multiple pleas for information about where he is buried. Since 1999, there have been four attempts to find him but both his parents died without finding their son.

The Independent Commission for the Location of Victims Remains (INLVR) is now trying again, having narrowed down the area to section of around an acre of bogland to try and find the teenager’s remains.

Senior investigator Jon Hill is a veteran of this type of search, having been involved with previous searches for the 16 men and women who were “disappeared” during Northern Ireland’s Troubles.

All but three of them have now been found. Some by chance and a number by the commission.

Mr Hill has the expertise of archaeologists on site but said this type of search is much more challenging than looking for antiquities.

“You either find them or you don’t,” he explained, rather than the usual archaeological practise of being able to narrow down which level of earth what they are looking for will be in.

He said an item of clothing is the first thing they find, and then a great deal of checking is carried out before they can have any certainty over what they have found.

“We are met here with very challenging ground surface and the searches that have taken place mean that a lot of material has been moved around, so everything is stacked against it, but we have been in this position before and we have had success in this position before,” Mr Hill said.

“We will search for as long as we need to search.

“It may well be that the weather will stop us from concluding this year and we may have to come back next year, but it is still worthy of searching and that is what we will do.”