Gardaí have reportedly found a gun during their excavation in Chapelizod as part of the Trevor Deely cold case.
The 22-year-old from Co Kildare disappeared after his office Christmas party in Dublin in 2000.
It is understood one line of inquiry for officers is whether Trevor was shot by a well known criminal before being buried in an area of scrubland near the banks of the Liffey.
The identity of the suspect came to detectives attention when new technology was able to enhance CCTV from the night Trevor Deely went missing.
Gardaí will have to establish whether the firearm has any connection to Trevor, whose body has never been found.