Three men, who were arrested on Monday, have all been released without charge.
Gardai have arrested a man as part of the investigation into the murder of a 17 year old boy in January 2020.
The man in his 20s is being held at a Garda Station in Dublin.
Three men, who were arrested on Monday, have all been released without charge.
Files will now be prepared for the Director of Public Prosecutions.

Gardaí Call Off Work-To-Rule At Last Minute
Small Parcels Can Now Be Sent Using New Drop-Off Service, With 84 Locations In Kildare
Body Found In Lough Erne Amid Search For Missing Limerick Woman
South Dublin Community In Shock After Six Teenage Pedestrians And Woman Taken To Hospital After Car Crash
Public Sector Talks Resume Later As Government Proposes Improved Offer
Yellow Fog Warning Issued For Kildare
Staff At RTÉ, Newstalk And Irish Independent Evacuated Following Bomb Threat
Public Sector Pay Talk Efforts Ramping Up As Strikes Loom