The Navy will today search an area off the Co Galway coast where three bales of cannabis were found in three loads at the weekend.
The last batch of the drug was brought ashore to Killybegs, Co Donegal, yesterday.
A trawler that was fishing about 50 miles off the coast of the Arran Islands on Friday found packages of cannabis in its nets. Two further finds were made by the ship on Saturday morning and evening.
The combined value of the three hauls is around €100,000.
Gardaí believe the drugs were dumped from a ship that got into difficulties off the west coast a decade ago.
The Irish Naval vessel LE Aislingwas at the scene at the weekend and was involved in a joint operation with the fishing trawler. The Customs Service cutter was also involved.
The LE Aislingwill return to the scene today and use specialised sonar equipment to scan the seabed.