DETECTIVES have been given another week to question Royal Marine Ciarán Maxwell arrested as part of a Northern Ireland terrorism investigation.
Maxwell, 30, from Larne, Co Antrim, was detained by Metropolitan Police officers in southern England in a planned swoop last week.
The investigation is linked to the discovery of two dissident republican-related arsenals in woodland in Northern Ireland earlier this year.
Police are again searching Carnfunnock Country Park near Larne as part of the probe. They found bomb-making items there in March.
Last Wednesday's arrest operation involved searches at a house and wooded area in south Devon. Searches at the property in Exminster and nearby Powderham New Plantation woods continued the following day.
Officers searched a number of properties in Larne last week and carried out fresh inquiries this week.
Maxwell is being detained on suspicion of preparation for acts of terrorism.
While the threat posed by violent dissident republicans in Northern Ireland has been classified as severe for a number of years, in May the UK intelligence services raised the threat level in Britain from moderate to substantial.
Two separate hauls of weapons were discovered in Carnfunnock and Capanagh parks within three months of each other.
Police said four barrels were unearthed at Carnfunnock - two were empty but two contained a variety of bomb-making components, including wiring, toggle switches, circuit boards, partially constructed timer power units, ball bearings and a small quantity of explosives.
An armour-piercing improvised rocket and two anti-personnel mines were among the cache recovered at Capanagh in May.
Several pipe bombs, magazines and ammunition for an assault rifle, and bomb component parts and command wires were also concealed in barrels in purpose-built holes in woodland.
Larne is predominantly unionist/loyalist, so the finds led to initial speculation that they could be linked to loyalist paramilitaries. However, after assessing the weaponry, police concluded they most likely belonged to dissident republicans.
The extremists intent on bringing about a united Ireland by violent means are small in number and capacity compared with the republican paramilitary organisations of the Troubles, but they still launch deadly if sporadic attacks on security forces.
Since 2009, dissidents have murdered two soldiers, two policemen and two prison officers in Northern Ireland.
