Archbishop Eamon Martin has said the relatives of the Disappeared, who include Donaghmore man Columba McVeigh, need a “mechanism of truth and information retrieval” to help get justice.
He was speaking at the Mass for the Disappeared at St Patrick’s in Armagh.
Sixteen people were abducted, murdered and secretly buried during the Troubles - four of them are still missing.
Columba McVeigh was kidnapped on 1 November 1975. His body has never been found, despite extensive searches.
Relatives who gathered for Sunday’s mass heard Eamon Martin urge anyone with information to come forward.
He suggested that trustworthy people in the church could accept and sensitively share secrets about where victims are buried.
Eamon Martin said: “There must be so many people walking around today who know in their hearts that the information that they have locked down inside them is capable of unlocking the uncertainty and grief of families.
“For our part, we need to find a mechanism of truth and information retrieval which will allow more of these people to come forward so that many more families can be set free from the agony of waiting and wondering, ‘why?’
“Even in the absence of a formal mechanism, I am confident that there are trustworthy people in society and in the Churches who would be willing, and could be empowered and enabled, to accept and sensitively share information in this regard.”
Searches have been led by the Independent Commission for the Location of Victims’ Remains, established in 1999 by an agreement between the British and Irish governments to obtain information in strictest confidence that may lead to where the bodies are buried.