Detectives confiscated a tonne of cannabis resin, with an estimated street value of €10m, and 30 kilos of cocaine, worth €3m, in an operation in Lusk, North County Dublin on Saturday.
Three men, two in their 30s and one in his 20s, were arrested.
Two are thought to be minor players, while the other is placed higher up the ladder.
The operation was carried out jointly by the Garda National Drugs Unit (GNDU) and the National Bureau of Criminal Investigation.
Earlier this month, the operation seized a record quantity of ecstasy from the same drug trafficking network.
Some 1.2 million ecstasy tablets, worth around €12m, were seized in the Ashbourne and Ballymun areas of North Dublin.
Two men were charged in relation to that haul.
The operation has dealt a substantial blow to a major international trafficking organisation, based in north Dublin, Spain and Amsterdam.
The gang is run by a 46-year-old convict from Dublin’s north-inner city, together with his two lieutenants, who are nicknamed ‘Fatso’ and ‘Baby Face’.
The drugs hauls in Lusk and Ashbourne were financed and organised by Fatso. Together, they had a street value of around €25 million.“He is on his knees financially. The cost of these hauls, together with sourcing the drugs and the logistics of the operation, is hitting him badly,” said a garda source.
He said it will also impact the gang’s supply network: “He might be afraid to keep up and running. He might be worried what the guys say or what further inroads might be made.
“However, they still seem to get back up and running.”
Gardaí are questioning the three men arrested at Balbriggan and Swords Garda Stations and can detain them until this Saturday.
The latest operations are not the first time the gang has been seriously hit by gardaí.
Last summer, the GNDU, seized an estimated €20m worth of cannabis in linked finds in North Dublin, belonging to the gang. A number of people were charged in relation to those hauls, including 36-year-old David Dempsey who was recently convicted.
The joint garda operation is the brainchild of Assistant Commissioner Tony Hickey, the new head of the Garda National Support Services.
The co-operation is expected to continue and will see other gangs targeted.
In other weekend seizures, gardaí seized almost €200,000 worth of drugs in separate searches in Limerick, Wicklow and Donegal.
In Limerick, the local drugs unit seized one kilo of cocaine and seven kilos of cannabis, with an estimated street value of €120,000.