He's being held at Castlereagh Garda Station under Section 30 of the Offences Against the State Act.
Gardai have confirmed the arrest is linked to an incident at a repossessed house in Co Roscommon last month.
A number of security personnel were assaulted in Falsk, Strokestown on December 16th last year.
They had been guarding a house where an eviction had taken place earlier in the week.
Meanwhile, another man who was arrested yesterday in County Mayo in relation to the same incident appeared in court today.
The man was brought before a special sitting of Castlerea District Court this morning, where he was remanded in custody to appear at Harristown District Court on this day week.
Statement in full -
|Court appearance and further arrest Strokestown Investigation|
A 54 year old man arrested on the 10th January as part of an investigation in an incident at Strokestown, Co. Roscommon has this morning appeared in court.
The man was brought before a special sitting of Castlerea District Court this morning, 11th January 2019 where he was remanded in custody to appear at Harristown District Court on January 18th 2019.
A second arrest was made this morning at 11th January following a search conducted in Co. Donegal. The man in his 50s was arrested under the provisions of Section 30 of the offences against the state Act, 1939. He is currently detained at Castlerea Garda Station.