Cannabis and cocaine were also seized by Gardaí in the search
Gardaí are questioning a man in his 50s after after seizing drugs with a street value of 2.5 million euro in the south inner city area of Dublin.
The discovery was made after a car was stopped and follow up search was carried out.
The drugs were found yesterday evening after a vehicle was stopped a subsequent search was carried out on a residential premises in the south inner city.
Some 15kg of heroin, with an estimated value of €2.1m, 22kg of cannabis herb with a value of €440,000 and cocaine believed to be worth €35,000 was seized.
£43,000 in cash (sterling) was recovered along with a hydraulic press, a vacuum packing machine, communication devices and other drug paraphernalia.
Garda personnel attached to the Garda National Drugs and Organised Crime Bureau, assisted by the Special Crime Task Force were involved in the operation.
The man is currently detained under Section 50 of the Criminal Justice Act, 2007 at Kilmainham Garda Station in Dublin, he can be held for up to seven days.

Tánaiste Indicates Carbon Tax Cuts On Home-Heating Oil
Seven In Ten Young Adults Considering Emigrating
Research Highlights High Level Of Energy Drink Consumption Among Young People
Taoiseach And Ministers To Travel To New York For UN General Assembly
Google Fined €403M Over Handling Of Location Data
Kildare TD Says He Won't Be Intimidated Amid Widespread Political Harassment Fears
Cabinet To Discuss School Meals Programme Amid Criticism Of Nutritonal Standards