The actor James Nesbitt has called on anyone with information about the North's "Disappeared" to give it up "in the name of humanity".
Mr Nesbitt said the recent death of his father, Jim, had brought home to him once again the pain felt by those who still waited for news of their lost loved ones.
He sent the message of support to the WAVE Trauma Centre in Belfast which held a ceremony on Sunday to mark the International Day of the Disappeared.
In Northern Ireland, the "Disappeared" refers to 16 people abducted, killed and secretly buried by republicans during the Troubles. The remains of all but three of the victims – Joe Lynskey, Columba McVeigh and Robert Nairac – have since been recovered.
Their relatives and the father of Lisa Dorrian – who went missing in 2005 and is believed to have been murdered – released doves in their memory as well as a fifth dove on behalf of people around the world who believe their loved ones are dead and have been secretly buried.
Nesbitt is a patron of the WAVE Trauma Centre and a supporter of the Families of the Disappeared.
“The death of a deeply loved family member is always hard to take whatever the circumstances,” said Nesbitt. “But to know that your loved one met a violent end and not to know where they were buried for years and years brings almost unimaginable pain and anguish.
“That is what the families of the Disappeared have had to endure.
“For the families of Joe Lynskey, Columba McVeigh, Robert Nairac and Lisa Dorrian that agony continues and will not begin to ease until they are brought home. Someone somewhere must have information that could lead to their remains being found,” he said.
The lead investigator with the Independent Commission for the Location of Victims' Remains (ICLVR), Geoff Knupfer, appealed to anyone with information to contact them.
“We are down to three cases now from 16 and while Lisa Dorrian’s disappearance is outside the ICLVR’s remit we hope that progress can be made there too.
“Anyone with information can be absolutely assured that it will be treated in the strictest confidence.
“We can only help these families if people with information come forward,” he said.
Anyone with information can contact Crimestoppers on 0800 555 111 or via an untraceable anonymous online form at crimestoppers-uk.org.
The ICLVR can be contacted by telephone on 00800-55585500 or +353 1 602 8655, by email at Secretary@iclvr.ie or by post at ICLVR PO Box 10827.
