Gardai hoped to arrest a number of people picking up consignments of cannabis from a shipment seized at the weekend but were forced to seize about half the £5 million haul before it was delivered.
About 450 kilos of cannabis resin were seized on Saturday. The cannabis was vacuum-packed in 21/2 kilo blocks and hidden in cardboard boxes under knitwear. About half the consignment had been dropped off from a truck in woodland four miles south of Cahir, Co Tipperary, at about 3.30 p.m.
Shortly afterwards, one man driving a Mercedes and two men in a Toyota Celica arrived at the Coillte-owned Kilcoran woodland, less than half a mile off the main Dublin to Cork road.
They drove up a side track in the woods and were loading the cardboard boxes into their cars when gardai, including armed officers from the Emergency Response Unit, moved in.
One of the men ran off through the trees and the other two were arrested. Almost immediately afterwards the truck carrying the remainder of the consignment was stopped by gardai outside Fermoy, Co Cork, and the driver was arrested.
Gardai believe there were several more drops to be made and some of the consignment was destined for Limerick.
A senior Garda source said it was felt that the surveillance operation had become too "strung out" and a decision was made to seize the haul before the next drop. The source denied that it was because the third man escaped that the consignment was seized.
A man was arrested at about 8 p.m. on Saturday night, about four miles from the woods.
The Cork-registered truck had been under surveillance by gardai from the National Drugs Unit and the Garda Surveillance Unit. The drugs are believed to have arrived in Dublin late last week.
Twelve people had been under surveillance for up to six months in an operation organised with the Cork Divisional Drugs Unit.
Det Supt Tim O'Callaghan said the seizure was a "serious dent in the operation of drug-dealers in the south-east, whether that is Cork, Limerick or Waterford".
Last night armed gardai were guarding the haul at Cahir Garda station. It is expected to be put on display in Dublin today.
Gardai and forensic experts searched the woodlands for any remaining drugs and any firearms. They concentrated on the area of trees where one of the suspects escaped from the scene.