Intelligence services had 24 hour surveillances on several weapons hides used by Royal Marine Ciaran Maxwell in an attempt to trap a 'big fish' after being alerted to the soldier's collusion with dissident republicans.
In total, officers found materials and chemicals which would have made tens of kilos of explosives from hides in Devon and over 100 kilos of explosives from the hides in Northern Ireland.
Among the haul, kept in 43 separate hides, was14 pipe bombs - four of which were deployed in Northern Ireland.
None of the pipe bombs had been used against members of the security forces. One was diffused by army bomb disposal in Cushendun, one tested in a forest and two failed to explode.
Two explosively formed projectiles (‘EFPs’) one with explosive fill, one without, of the same type used by the 'New IRA' in an attack on a police land river in west Belfast in March 2014 were also recovered.
Three fully constructed improvised detonators and other components parts for improvised explosive devices IEDs, again of a type used by the 'New IRA'.
A quantity of military grade explosives, of a type discovered in a previous haul of weapons in Larne in February 2013 supplied by Maxwell, is thought to have also fallen into the hands of 'active' republicans.
Dissidents from the 'New IRA' boasted of having used a new type of explosive in an undercar bomb in Derry in February of this year.
The device fell from a car of an off duty police officer in the Ardanlee area of Culmore and failed to explode, leading to speculation component parts had been tampered with before falling into the hands of the group.
In a coded statement the organisation claimed it featured an "explosive it had not used before and was of a new design" and was of a "new type of tilt switch, detonator and plastic explosives".
The make up of the device is thought to have included military grade components of the type contained in the Maxwell haul.
Intelligence services were alerted to the activities of Maxwell since 2013 and placed around the clock surveillance on a number of the hides in an attempt to trap leading dissident republicans who had made contact with the soldier.
Covert pictures of Maxwell entering a wooded area in Devon, where he had stashed some of the weapons, was released by the Metropolitan police following the sentencing of the former soldier, who has since been discharged from the Marines.
However, images from surveillance carried out by MI5 was not released with intelligence services keen not to reveal the methods used in Northern Ireland to track the Larne man.
Information provided by Maxwell, who cooperated fully after his arrest, is thought to given police an insight into the merger group who remain under constant surveillance.
