Paramilitary involvement is one line of inquiry in the investigation of the spate of ATM robberies on both sides of the border.

Since December, thieves have stolen 11 cash machines from businesses in Northern Ireland and in counties Monaghan and Cavan.

Graphic CCTV footage of the weekend ATM robbery in Dungiven, Co Derry, illustrated the brazen efficiency of the gang involved.

In recent years, police on both sides of the border have used a range of tactics to counteract patterns of serious crime. Surveillance, technology and the use of informants have featured in PSNI and Garda strategies.

But so far with ATM robberies, the gangs are winning - and investigators have made no significant breakthrough.

The absence of a justice minister and an Assembly at Stormont means public concern is not being ventilated at a political level.

But in communities served by a dwindling number of banks, the ATM facility is a necessary resource. 

Security sources acknowledge that paramilitary involvement is one line of inquiry. Highly-organised, mobile criminal gangs is another.

Last night Minister for Justice Charlie Flanagan stated the necessary resources are being provided to the gardaí for what is an island of Ireland challenge.