Gardaí and Customs have seized over €8m of heroin in a plane at Weston Airport.
It is the largest seizure of the drug this year.
The light aircraft was searched and up to 60kg of vacuum-packed heroin was found in holdalls.
Two men in their 40s and 60s have been arrested. One man was arrested on the plane, and the other nearby.
They are being detained under drugs trafficking legislation at a Co Kildare garda station and can be questioned for up to seven days.
The light aircraft has also been seized and gardaí are now tracing its flightpath.
Gardaí say the seizure follows an intelligence-led operation involving the Drugs and Organised Crime Bureau and Revenue Customs.
Detectives say the drugs were sourced by a family-based west Dublin gang with links to the Kinahan Organised Crime Group and were for distribution in Dublin and around the country.
The gang had been under surveillance and the seizure was made around midday.