A serving Royal Marine was arrested in Somerset, England, on Wednesday as part of an investigation into a Northern Ireland-related terrorist threat.

Ciarán Maxwell, 30, from Larne, Co. Antrim, is believed to have been taken into custody this week by officers from the Metropolitan Police Service's Counter Terrorism Command on suspicion of preparation for acts of terrorism. He was detained in a pre-planned swoop on his base in Taunton, Somerset in relation to two major dissident republican arms finds in Northern Ireland in March and May of this year.

Several UK police forces and MI5 (Britain's FBI) were involved in searches of houses in Devon in England and Larne in Northern Ireland. They were conducted at the same time as Maxwell’s arrest, as well as a search of a wooded area near the house in Devon. At least two houses were searched on the Old Glenarm Road in Larne, one of which was the suspect’s family home, by heavily armed police supporting forensic investigators.

The properties in Larne are located close to two forest parks where weapons dumps were discovered earlier this year. The two separate hauls of weapons were discovered within three months of each other in Carnfunnock and Capanagh parks.

Bomb-making materials –  including wiring, toggle switches, circuit boards, partially constructed timer power units, ball bearings and a small quantity of explosives – were found in March in Carnfunnock Country Park.

Just weeks later in May, an armor-piercing improvised rocket, two anti-personnel mines, several pipe bombs, and magazines and ammunition for an assault rifle were among the weapons discovered in a separate cache at Capanagh.

After examination, the police concluded that both weapon discoveries were linked to dissident republicans, despite the fact that the local area is predominantly Unionist/Loyalist.

The Belfast Telegraph reported that Maxwell, who has a Catholic mother and Protestant father, was the victim of sectarian bullying throughout his teenage years.

"He grew up in the Seacourt estate and was absolutely tortured by the UDA when he was a teenager,” a local man told the Larne Times shortly after an attack in 2002 which left the teenage Maxwell with a fractured skull and multiple other injuries.

According to an article published by An Phoblacht, when he was 16-years-old Maxwell was subjected to a savage beating by a loyalist gang, which attacked him with iron bars and golf clubs.

"He was struck by a bottle and fell under the blow. Kieran struggled to his feet and despite losing a shoe, tried to run away. At this point up to ten loyalists arrived in two cars. This gang was armed with iron bars and golf clubs and they immediately attacked Kieran. He was beaten to the ground and lost consciousness.”

Read more: Gerry Adams warns dissidents on threats against the community

British Marine arrested today and accused of Northern Ireland-related terror offence is named as Ciaran Maxwell.

— steve swann (@steveswannBBC) August 24, 2016

Ciaran Maxwell, who is being questioned over alleged terror offences was reportedly badly beaten by loyalists in Larne when he was 16.

— Siobhan Robbins Sky (@SiobhanRobbins) August 25, 2016

Maxwell is now believed to live at the address searched in Exminster, Devon, with his partner Kerry O'Callaghan, 29, and a young child. He serves with the (Royal Marines unit) 40 Commando.

"We are aware of a police investigation involving the arrest of a member of the Armed Forces under the 2000 Terrorism Act and will assist this investigation fully,” said a spokesperson from the English Ministry for Defence.

"It would be inappropriate to comment further on an ongoing investigation."

Arrested at 12:20 BST by Met detectives supported by officers from Avon and Somerset and Devon and Cornwall Police, Maxwell is being held in West Country Police Station. His arrest is said to been a culmination of months of police work.

"Local officers will be in the Exminster area and will be speaking to residents to help offer reassurance,” said Detective Chief Inspector Antony Hart, of Devon and Cornwall Police.

"Searches are expected to continue throughout the weekend at the property in question. Searches are also continuing at the nearby wooded area.”