Cocaine worth more than €50m has been discovered concealed in a shipment of bananas, with much of the haul destined for Ireland's lucrative drug market.
Last night, senior sources said that "a number of Irish drugs gangs chipped in" towards a portion of the massive drugs haul.
Gardai had gathered details of the smuggling operation by bugging the phones of Irish criminals based abroad.
Approximately 300kgs of the narcotics were discovered on the cargo ship Star Stratos when British police swooped on the boat in Portsmouth on Monday evening.
The seizure represents a major disruption to Irish criminal elements before Christmas. The operation involved cooperation between gardai and the UK's National Crime Agency (NCA).
Sources have refused to rule out the involvement of Christy Kinahan's international crime syndicate. However, they said the indications were that "several Irish gangs" invested in the shipment.
"Of course Kinahan's gang have to be considered because of the scale of this. But the most likely scenario is that a number of different groupings have clubbed together to take advantage of the boom Christmas market for cocaine," a senior source said.
It is understood that over the past fortnight around 10 officers from the Garda National Drugs Unit (GNDU) worked alongside officers from the NCA as part of the surveillance operation before the cargo ship was searched.
As part of the top secret operation, gardai gained key information through the bugging of phones of Irish criminals based abroad.
The NCA said investigations were continuing to find the organised crime groups likely to be responsible.
Deputy director Tom Dowdall said: "Working with our law enforcement partners in the UK and Ireland we have successfully prevented a huge quantity of what is likely to be very high purity cocaine reaching our streets."
This is the second joint operation between the NCA and gardai which has resulted in a large cocaine seizure in less than three months.
In September, around a tonne of cocaine was seized by the Irish Naval Service from the yacht Makayabella about 480km off the south west coast of Ireland.
The passage around the south-west coast of Ireland has been well used in recent times by drugs smugglers bringing shipments from South America and Africa into Europe.