The criminal figure, from Dublin’s northside, is being linked to the 30kg of MDMA (ecstasy) crystalline powder and 20kg of ketamine seized in a joint Customs and Garda operation.
The haul is estimated to have a final street value of about €3m.
The 38-year-old drug boss has been linked with the murder of Real IRA boss Alan Ryan six years ago.
The seizure on Tuesday afternoon was a joint intelligence-led operation by Revenue’s Customs Service and the Garda National Drugs & Organised Crime Bureau.
A van was stopped in Kilbarrack, north Dublin and the ecstasy and ketamine was found. In a follow-up search, 1kg of herbal cannabis (€20,000) was seized at a house in the area.
A 43-year-old male was arrested and detained under the Drug Trafficking Act.
The seizure is thought to be one of the largest hauls of both ecstasy powder and ketamine in recent years.
Gardaí are concerned at a recent spate of ketamine seizures, including hauls in Tallaght and Clondalkin in March, a seizure in Dublin Port the same month and a seizure in Co Carlow last May.
“The seizures have been quite significant, with a couple of 4kg to 5kg ones,” said one garda source, “but this one is much larger again.”
Ketamine, also known as K, became a controlled drug in 2011 and is considered a powerful hallucinogenic. It is used recreationally indoors, in house parties, clubs and festivals.
It can be used legally as an anaesthetic, but in its illicit form acts as a “dissociative drug”, where people can feel detached from their body and environment.
Dr Eamon Keenan, HSE addiction lead, said ketamine has been linked to mental health problems, including panic attacks, depression and delusions.
He said the HSE published a leaflet with USI last year on ketamine and was included in packs for Gay Pride, noting that the drug seemed to be used in that population.
“It seems among young people it is becoming more common as a drug,” he said.