The Garda water unit has been drafted in to help in the search for missing man Trevor Deely on the three-acre site in Chapelizod, Dublin.
The investigation, which has entered its fourth week, is set to focus on four different locations within the site.
The Irish Times understands that the Garda water unit is to conduct a search of part of the river Liffey which runs alongside the woodland in Chapelizod on Monday afternoon.
The 22-year-old was last seen on December 8th, 2000 when he vanished near Haddington Road in Dublin’s south inner city.
“We have now entered the fourth week in our investigation and we are confident of a break-through in the case. We will be carrying out targeted searches within the site over the next couple of days on three or four different zones which we have identified.
“As part of this, members of aqua unit have arrived on site to assist in our ongoing investigation,” a senior source told The Irish Times.
The site in west Dublin has been cleared of trees and other vegetation to allow extensive excavation to begin with specialist equipment this week and gardaí are “confident” in a breakthrough in the case.
Gardaí began searching the site in Chapelizod four weeks ago after receiving a tip-off that the 22-year-old’s body was buried there.
Gardaí are working off information suggesting Mr Deely was shot dead by a known criminal that he had a chance encounter with in Dublin’s south inner city.
Hopes of a breakthrough in the case were raised when gardaí recovered a gun in the first week of the search but sources have downplayed the significance of this being connected to Mr Deely’s case.
The man identified as the suspect was active in drug dealing and armed robbery and living off the earnings of prostitution at the time.
Mr Deely (22) was last captured on CCTV passing the Bank of Ireland ATM on Haddington Road at 4.14am on December 8th, 2000.
In April gardaí published enhanced CCTV images showing him conversing with an unidentified man during his last known movements.
The enhanced footage captures a man dressed in black outside the rear entrance of Bank of Ireland’s asset management offices on Wilton Terrace, Dublin 2, where Mr Deely worked. The man appears at 2.59am and takes cover behind a pillar. He waits there for approximately 35 minutes.
At 3.34am, moments before Mr Deely approaches his place of work, the man steps out onto the footpath and follows Mr Deely to the back gate of the bank, before conversing with him for a few moments.