A man in his 20s has been arrested in connection with the murder of James Kenny McDonagh, the man whose remains were found near Tallaght earlier this month.
The remains of Mr McDonagh, who had been missing since October 2010, were discovered scattered over a wide area and are believed to have been moved by an uprooted tree.
Two hillwalkers made the discovery at Slieve na mBan Óg mountain, about 14km from Tallaght.
The man arrested today is being detained under the provisions of section 30 of the Offences Against the State Act 1939 at Kilmainham Garda station, a Garda spokesman said.
Dubliner Mr McDonagh was 28 years old when he was last seen in late October 2010.
His car was found abandoned at Peamount Hospital in Newcastle, Co Dublin, shortly afterwards and there had been no trace of him despite an extensive search, until the remains were discovered earlier this month.
Gardaí were working on the assumption that he was abducted and killed by a west Dublin gang.
They have appealed for anyone with information to contact them at Kilmainham Garda Station on 01-666 9700, the Garda Confidential Line 1-800-666-111 or any Garda Station.