A sixth dig is to be carried out by an expert team searching for a teen who was abducted and murdered by the IRA in November 1975.
Columba McVeigh was shot and secretly buried during the Troubles.
The 19-year-old from Donaghmore in Co Tyrone is one of four people who remain missing after the bodies of 13 others classified as the Disappeared were uncovered.
Investigators from the Independent Commission for the Location of Victims' Remains (ICLVR) have returned to Bragan Bog near Emyvale in Co Monaghan. They will search an area of around two acres.
The news comes after five previous searches were carried out since 1999, covering a total of 21 acres, with the most recent being in September 2019.
Lead forensic investigator, Geoff Knupfer, said his team remains convinced that the teen was buried in the bog and that this new search would not be taking place "unless we believed that there was a credible reason for doing so".
He also urged anyone who knows anything that could help recover Columba's remains to contact the team.
Jon Hill, senior investigator with the ICLVR, added: "There is an additional challenge in that part of the area is forested, but we'll deal with that if we have to further down the line," he said.
"We are working with a highly experienced team of contractors and archaeologists, and we will do our utmost to bring this search to a successful conclusion for the McVeigh family. We all know how much it would mean to them."
The bodies of three others remain uncovered, including former monk Joe Lynskey, former British soldier Robert Nairac and Seamus Maguire, whose name was added to the lost in February this year.
Mr Maguire disappeared after leaving his home near Lurgan in County Armagh about 50 years ago.
The Provisional IRA has admitted responsibility for 13 of the abductions and murders, while another Republican paramilitary group, the Irish National Liberation Army (INLA), has admitted one.
An anonymous donor has put up a reward of $60,000 (US) for information that results in the recovery of the remains of the four outstanding victims.
Anyone with information relating to the whereabouts of the remains of the four men is asked to contact the UK charity CrimeStoppers on 0800 555 111 or use an untraceable anonymous online form at www.crimestoppers-uk.org.
The ICLVR can be contacted by telephone on 00800-55585500 (internationally) and 01-6028655.
READ NEXT:
- Ryan Tubridy explains Vicky Phelan's absence on Late Late Show as health update shared
- 174 football fans killed in mass riot involving tear gas as league suspended
- Met Eireann's good news for all but two areas this weekend before grim change next week
- Full list of energy companies hiking bills this weekend as customers rush to submit meter readings
- Disabled mum describes nightmare as her Ryanair flight takes off as she watched from special assistance vehicle
Get breaking news to your inbox by signing up to our newsletter
