His body was found by a forestry worker in Blessington.
Gardaí at Baltinglass have arrested a man aged in late 30s as part of an ongoing investigation into the murder of Paul 'Frank' Byrne, whose remains were discovered in Blessington on 29th July, 2010.
The man was arrested on Monday morning in the Dublin area.
He was taken to Baltinglass Garda Station where he is currently detained under Section 4 of the Criminal Justice Act.
This is the 5th person arrested to date in connection with this investigation.
Gardaí say the investigation is ongoing.
Paul 'Frank' Byrne (20), was last seen on 15th July, 2009 at Kilmartin Green in Tallaght.
He was reported missing to Gardaí at Tallaght Garda Station by his mother on 16th July, 2009 and a Missing Persons investigation was then launched.
The investigation was subsequently taken over by Gardaí in Baltinglass following the discovery of Paul 'Frank' Byrne's remains by a forestry worker felling trees in a remote area at Ballyfolan in Blessington on 29th July, 2010.
Identification of his remains was made by way of DNA profile.