CUSTOMS investigators in the Republic have arrested a man from Northern Ireland.
It followed the discovery of two fuel laundering plants in Co Monaghan.
The 27-year-old man from Armagh was arrested after a raid at Killyneill, less than a mile from the border.
He was taken away to be questioned at Monaghan Garda Station.
Investigators discovered the plants in a private yard and a commercial premises and could six million litres of diesel a year.
That amounts to a loss the Republic’s public purse of £2.9 million (€3.5 m).
A diesel laundry was found at one of the premises when it was raided by customs officers last year.