The family of Trevor Deely say they have a better chance of finding him if they keep his name alive.
The 22 year old Bank of Ireland worker was last seen in December 2000 walking home from his Christmas Party in the Baggot Street area. Trevor's brother Mark has spoken out as part of National Missing Person's Day.
He admitted it is "unrealistic of us to expect people to remember where they were on that weekend, but I think it's entirely feasible for people to go on to garda.ie website and have a look at the CCTV footage".
"If we keep his name alive, we have every chance of actually trying to find what happened him and where he is", Mark said.
Trevor's last known movements were captured on CCTV, which was enhanced earlier this year with improved technology.
It shows a man dressed in black acting suspiciously outside the rear entrance of Bank of Ireland, Asset Management Offices on Wilton Terrace between 3am and 3:34am, prior to Trevor arriving.
At 3:34am, just moments before Trevor approaches his place of work, the footage shows a man stepping out onto the footpath and following Trevor to the back gate of Bank of Ireland before chatting with him briefly at 3:35am.
Trevor was last captured on video passing the Bank of Ireland ATM machine on Haddington Road at about 4.14am on the 8th of December 2000.
Gardaí believe that the man acting suspiciously outside of Trevor’s workplace is the same man that is seen passing the Bank of Ireland ATM on Haddington Road at 4.14.am, just moments after Trevor Deely.
Gardaí investigating the disappearance of Trevor Deely carried out a search of woodland in Chapelizod in August after they recieved new information.
After weeks of digging, officers said that "Unfortunately nothing that furthers the search for Trevor was located during the search."