Gardaí have seized 133 kilograms of cocaine, which they say was destined for Ireland.
The discovery was made by the Garda National Drugs & Organised Crime Bureau (GNDOCB) along with the Drug Control Police (PCD) of the Ministry of Public Security in Costa Rica.
The drugs were concealed in a cargo of fruit on board a ship named Polar Chile.
The cocaine seized has a potential value of €10m.
Assistant Commissioner John O'Driscoll confirmed involvement of An Garda Síochána and Customs & Revenue in the investigation.
He said international cooperation involving law enforcement organisations on a global basis 'is essential' in targeting the criminal activity being engaged in by organised crime groups that have an international dimension.
In a separate, unrelated case Gardaí are believed to be assisting Spanish police following a huge seizure of cannabis on the Costa Del Sol.
A number of Irish citizens are understood to be among 11 people arrested after police seized seven tonnes of cannabis, with an estimated street value of €18m.
