Gardaí say the seizure of 15 kilos of heroin is the single biggest seizure in the history of the State.
The heroin has been valued at around £5 million but is uncut so could have a street value of three times that.
The largest single heroin seizure in the history of the State has dealt a major blow to the south city drugs gang that organised its importation.
The haul was discovered when detectives from the National Drugs Unit stopped and search a van in Lucan in the early hours this morning. They also found over 100,000 ecstasy tablets worth over £1.2 million.
In a follow up search at a flat in Kilmainham, a further half kilo of heroin and two imitation firearms were discovered.
Detective Superintendent Noel White of the Garda National Drug Unit said it was a very significant seizure and said that those responsible would be suffering a severe financial loss.
Five people have been arrested and are being questioned at Blanchardstown and Kevin Street Garda Stations. Two of those arrested are suspected to be key figures in the drugs gang responsible.
The drugs were brought in from London last week. The ecstasy came from Amersterdam and the heroin came from either Turkey or Afghanistan.
An RTÉ News report broadcast on 18 September 2001. The reporter is Paul Reynolds.