Gardaí have arrested a man in his late 20s as part of the investigation into the murder of 17-year-old Keane Mulready-Woods in January 2020.
The man is being held at a Garda Station in Dublin for questioning.
Three men, who were arrested on Monday as part of the investigation, have all been released without charge.
A file will now be prepared for the Director of Public Prosecutions (DPP).
Keane Mulready Woods was last seen alive by his family on the evening of Sunday, January 12, 2020.
He was killed and his body was later dismembered.
Remains found in Priorswood, Coolock in Dublin and in a burned-out vehicle at Trinity Terrace, Dublin 3, were those of the missing boy.