Eleven million pounds worth of cannabis was discovered by Irish customs officials in a joint operation involving police drugs units in the North and Britain.
Details are today emerging of the discovery of three tonnes of cannabis resin at Dublin port on Tuesday.
Police in Britain and Northern Ireland were alerted to the discovery by the Garda National Drugs Unit, which led to the arrest of four men in Harlow, Essex, yesterday and subsequent seizure of the drugs. The men are being held under British drug trafficking legislation.
The drugs were monitored en route to their intended destination in England, where the National Crime Squad arrested two men unloading the cannabis at an industrial unit in Harlow, last night.
Shortly afterwards, two further arrests were made nearby. Three tonnes of cannabis, compacted into small parcels and concealed in 60 boxes, were recovered. All four men are thought to be from the Essex area.
The £11 million shipment originated in Durban, South Africa, and was detected as a result of an ongoing monitoring operation by Gardai and customs officials. The seizure has resulted in the closure of one avenue of drug trafficking into the country, a Garda spokeswoman said.
South African police told ireland.comtoday that Durban is used as a port for drugs originating in Nigeria but would not confirm whether they were involved in the operation.
A fifth man was arrested in Essex in connection with the seizure this morning.