Gardaà say the amount has an estimated value of â¬2,800,000.
Investigating Gardaà at Milford are liaising with the Garda National Drugs and Organised Crime Bureau and the Police Service of Northern Ireland in respect of this probe.
Superintendent David Kelly in Milford - who is leading the investigation into the seizure - called it "significant".
He said in a statement: "This significant seizure has reduced the supply of illegal drugs in our community thereby increasing community safetyâ.
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