A search operation has resumed for the remains of Columba McVeigh at a remote bog in Co Monaghan.
The teenager from Donaghmore in Co Tyrone, was 19 when he was abducted, murdered and secretly buried by the IRA in 1975.
This is the second phase of the sixth search by the Independent Commission for the Location of Victims Remains (ICLVR).
The operation here - involving a team of contractors and archaeologists across a two acre site in Bragan Bog, close to Emyvale - started in October 2022 but was suspended in November due to poor weather conditions.
Speaking on a visit to the scene Mr McVeigh’s sister Dympna Kerr said she want her brother’s remains found so he can be given a proper burial.
There were 17 Disappeared cases during the Troubles in Northern Ireland. The remains of 13 people have been recovered.
The commission is appealing to anyone with information that can help in locating Mr McVeigh - as well as Joe Lynskey, Robert Nairac and Seamus Maguire - to contact them amid assurances the information will be treated confidentially.
Lead Investigator with the ICLVR Jon Hill said that if the remains of Mr McVeigh are in this particular part of the Monaghan bog, they will be found.
Phase one of the search would "methodically" work its way up to the tree line, he said.
"Clearly we hope we find Columba before then but if we have to clear a section of the forest then we'll do it," Mr Hill said.
"Every time we undertake a search the thoughts of everyone involved are with the McVeigh family.
"Our focus is on doing everything we can to bring this search to a successful conclusion."
The search is resuming one week before the 25th anniversary of the Good Friday Agreement.
Ms Kerr said that the agreement was to bring "a new beginning, a new dawn of hope, and for many, including us, it did".
However, Ms Kerr said that "there is still a dark, thick cloud that hasn't lifted for our family and the other families who are still waiting to bring him home".
She said that the renewed search for her brother brought both hope and anxiety.
"Of course we hope that this time Columba will be found but those hopes have been dashed so many times before that there still is that gnawing feeling in the pit of my stomach. Please make it this time," she said.
Ahead of US President Joe Biden's visit to Northern Ireland next week to mark the anniversary of the Good Friday Agreement, Ms Kerr said she hoped that he would be "made aware of the plight of the families of the Disappeared still waiting for a resolution".
"President Biden will rightly be proud of the role played by the USA in our peace process," she said.
"And President Clinton did so much for the families of the Disappeared.
"But President Biden needs to know that there is unfinished business and that there are Irish men and women who every day and every night still have to live in this horrible limbo. It has to end."
Speaking at a gathering for families of the Disappeared organised by the WAVE Trauma centre, Ms Kerr praised the work of the ICLVR, who she said "will do their utmost" to find her brother, and who "have done an amazing job in recovering so many of the remains of those hidden".
She said that that work can only be successful if they have the right information, which up to this point, they have not had.
"I hope and pray that now they do," she said.
M Hill appealed to anyone who has information about where Mr McVeigh is buried to come forward and not to assume that it is no longer relevant because this search had recommenced.
"If anyone has any information in relation to Columba's disappearance, however insignificant they may think it is, they should get it to the commission," Mr Hill said.
"We are entirely information driven. Any information that comes to us is treated in the strictest confidence and will never be used for any other purpose than to find the remains and return them to their family."
People who have information about Mr McVeigh or any of the other three outstanding "disappeared" cases can contact the ICLVR.
With additional reporting by Fergal O'Brien
