The Naval Service, Customs and the Garda have foiled a major drug smuggling operation when they detained a yacht with up to €80 million worth of cocaine off the south west coast of Ireland.

The Joint Task Force operation involved the LÉ Roisin and the LÉ Niamh detaining the 18.9metre yacht, Makayabella, carrying an estimated one tonne of cocaine on board at around 3am yesterday morning some 250miles off the Mizen Head in West Cork.

An armed boarding party from the LÉ Niamh boarded the yacht, which was being crewed by three Britons who were in an exhausted state and offered no resistance. They complied immediately with the demand to hand over control of the vessel to the boarding party.

The three men, who are from West Yorkshire, were then transferred to the LE Roisin where they were detained and both naval ships began escorting the Mayakabella to the Naval Base at Haulbowline in Cork Harbour where she is estimated to arrive at 9pm.

According to Joint Task Force statement, the LE Niamh, supported by the LE Roisin “postively identified a suspect vessel in a covert operation” and said the boarding was carried out “at night and in challenging conditions”.

The detention of the yacht by the Joint Task Force which involved members of the Garda National Drugs Unit as well as Custom Officers participating on the mission was the result of an international operation.

The Irish Times has learned that the National Crime Agency in the UK and French customs received intelligence on the planned shipment of cocaine from the Carribean to the UK and passed on the intelligence to the Maritime Analyis Operation Centre Narcotics in Portugal.

The Maritime Analysis Operations Centre- Narcotics, which is based in Lisbon and co-ordinates anti-drug trafficking actions by several European Union states, then tasked the Joint Task Force to intervene and detain the yacht off the south west coast of Ireland.

Initial reports suggested that the yacht originated with its drug cargo in Venezuela and initially it was thought the consignment was destined to rendezvous with a coopering vessel or collection vessel off the UK for importation into Britain.

International drug smuggling gangs use local boats to cooper or rendezvous with the transatlantic vessel as being local boats, they do not arouse the same suspicions that a new and unfamiliar boat might arouse in small ports along the south coasts of Ireland or the UK.

Meanwhile the National Crime Agency in the UK has begun its own parallel investigation as part of the international operation and has already arrested one man in the West Yorkshire area for questioning about the drugs shipment.

It is believed that the yacht, which was built in Rhode Island in 1986 and more recently was available for charter in the Grenadines in the Carribbean, left Venezuela several weeks ago on its trans-atlantic voyage.

The seizure is one of a number off the south west coast of Ireland in the past 15 years with many international drug traffickers seeking to land large consignments of drugs in isolated and remote harbours in West Cork for transhipment on then to the UK.