A 57 year old man was detained in the Lurgan area of north Armagh under section 41 of the Terrorism Act.
Detective Chief Inspector Gareth Talbot said: “The man has been taken to the Serious Crime Suite at Antrim Police Station where he is assisting police with their enquiries.”
The police officer wife disturbed a dissident republican terrorist as he placed the UCBT under their car parked in the driveway of their Glenrandel home in Eglinton last week.
Three men were later arrested in Co Donegal but were subsequently released pending a report to the Director of Public Prosecutions.
A 27-year-old man was arrested in Eglinton for questioning but he too was later released without charge.