The drugs were seized following the search of the cargo vessel Star Stratos at Portsmouth port yesterday evening.
Approximately 300 kilos were discovered concealed within a shipment of bananas which had originated in Colombia.
Investigations are continuing both in the UK and Ireland in conjunction with An Garda Síochána.
Deputy director Tom Dowdall, from the National Crime Agency’s Border Policing Command, 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.
“Our investigations into the organised crime groups likely to be responsible for this shipment continues.
“This seizure once again demonstrates the international reach of the NCA and the impact we are having on the criminal networks involved in drug trafficking.”
Border Force Regional Director Carole Upshall said, “Border Force officers are on the front line of the fight to stop illegal drugs like cocaine making it on to the UK’s streets and causing harm to our communities.
“Working with the NCA we are determined to do all we can to tackle traffickers and the criminal groups behind smuggling.”
This is the second joint operation between the NCA and An Garda Síochána which has resulted in a huge 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 around 300 miles off the south west coast of Ireland.
The NCA has over 300 border investigators at major ports, investigating detections of drugs, firearms, cash and other non-fiscal crime made by Border Force. The Border Policing Command also has an extensive overseas network of around 120 officers covering over 150 countries around the world.