Detectives believe they have smashed an international drug trafficking operation running through Ireland to the UK after seizing more than €2m of heroin at Dublin Airport.
The bust was made on Friday when gardai swooped on two Pakistani nationals during a drug exchange.
A child was also taken along by a female suspect during the exchange, and gardai believe the youngster was used as a cover.
The woman, aged in her 50s, was under surveillance when she entered the arrivals hall with the child to pass on the heroin to a man in his 30s.
The man had just landed in Dublin on a flight from Lahore, Pakistan.
Members of the Drugs and Organised Crime Bureau (DOCB) searched the woman's luggage and 15kg of heroin with an estimated street value of €2.1m was seized.
The two adults were from Pakistan but also have UK passports, a source said.
Detectives are now investigating if the pair were part of a drug trafficking operation using Dublin as a portal to deliver drugs into the UK.
"This seizure was the result of a lengthy investigation into drugs being trafficked into Ireland," a source told the Herald.
"At this stage it seems the heroin may have been brought here to get easier access to the UK.
"Gardai believe the drugs were due to be moved by ferry to England.
"If this proves to be the case, it's an example of how Ireland is being used as a portal to ship drugs into England, which has been ongoing for decades."
The man and woman were arrested by gardai and are being held at Ballymun Garda Station.
A garda spokesman said the operation was carried out with the assistance of the Revenue Customs Service.
In a separate operation on Saturday morning, Revenue officers seized 285 litres of wine at Dublin Port.
The alcohol was found when officers stopped and searched a car that had been on a ferry from France.
The seized wine has an estimated value of €4,000, which Revenue said would have amounted to a loss of €2,000 to the Exchequer.