He was taken into custody on Thursday in Lurgan.
Four other men arrested after searches in the County Armagh town and in Coalisland, County Tyrone, on Wednesday, are still being questioned.
Police evacuated an estimated 15 homes in Lurgan's Woodville Avenue during Wednesday's searches.
Forensic teams and police using a sniffer dog carried out the searches.
Three men, two aged 22 and one aged 24, were arrested in Lurgan and a 46-year-old in Coalisland.
A 22-year-old man who was arrested by police investigating dissident republican activity has been released unconditionally.