Sub-aqua units attached to Dublin Gardai have now begun searching a sector of the River Liffey, close to where authorities believe the body of Trevor Deeley may have been placed.
The 22-year-old Bank of Ireland worker went missing on December 8, 2000. He was last seen near Haddington Road in Dublin on the date, and has not been seen or heard from since.
The case went cold for over a decade, but recent new evidence triggered a review of the case.
Gardai released CCTV footage portraying a man acting suspiciously in the area near where Trevor was last seen at the time. Investigators are working off the theory that Trevor may have been shot dead by a known criminal with whom Trevor may have had a chance encounter.
A wooded area in Chapelizod was recently searched by ground units. A portion of the Liffey that runs alongside it is now the target of the search.