A close associate of Karl Fay was one of 29 criminals arrested this week as part of the major undercover drugs investigation Operation Trident.
Fay's associate was one of the youngest criminals arrested in the operation, while a grandfather with very close links to 'Fat' Freddie Thompson was the oldest.
The suspects were picked up as part of the five-month probe in Crumlin.
Sources say that gardai still plan to pounce on 40 more drug dealers in the coming weeks.
"This operation is still ongoing ,but it is already being viewed as a major success," said a source.
Undercover gardai spent over five months living near gang members and purchasing large quantities of drugs to infiltrate the mob formerly led by 'Fat' Freddie Thompson.
Detectives from the Garda National Drugs Unit and Crumlin Garda Station, backed by the Emergency Response Unit, swooped in the Crumlin area on Wednesday and Thursday.
Associates of Karl Fay were among the top targets of the operation.
Fay was the intended target when his 16-year-old cousin Stephen Hynes was shot in the back in Crumlin last October.
That was the third gun attack Fay has survived in 18 months.
He had spent several months away from Ireland after being warned that his life was under threat after he was shot in a park in Milltown, south Dublin, in April 2011.
The young man stumbled into the well-known Dropping Well pub covered in blood, and fell on the floor in front of shocked customers.
He made a full recovery after spending weeks in hospital.
In October 2011, Fay's family home in Crumlin was targeted in a pipe bomb attack after he had a major disagreement with an up-and-coming Crumlin criminal.
A source explained: "Traditionally, undercover gardai have been involved in buying drugs at street level, but this operation was different because it targeted criminals who were higher up the food chain."
In a series of stings, the undercover gardai purchased significant quantities of drugs from dealers having gained their trust.
"Some gardai actually moved into houses in the locality of where these gangs are operating so that they could observe exactly what was going on," the source explained.
"Some of those arrested have been caught selling sizeable amounts of heroin and crack cocaine to undercover gardai."
The criminals ended up trusting the undercover gardai so much they even held strategy meetings with them.