A pipe bomb.
A man in his 30s was arrested on Monday in relation to unlawful possession of firearms on the M7 in Mountrath in February 2016.
It is understood that he is being detained at Portlaoise garda station for questioning.
It is understood that the incident that happened in February 2016 relates to a pipe bomb in a car at a Toll plaza. The man went on the run and was arrested in the UK and extradited to Ireland to be questioned in relation to this offence.
He was arrested from Mountjoy prison to be questioned at Portlaoise garda station.
It is understood the man is from the Dublin area.