Almost €130,000 in cash, bank drafts and cheques was found in a car being driven by a member of Brian Rattigan's crime gang.
When gardai stopped the untaxed Mercedes-Benz at an armed checkpoint in Kilworth Road, Drimnagh, they found €15,000 in cash on the front passenger seat.
A search of the boot revealed €30,000 in cash, €41,000 in cheques and €42,000 in bank drafts.
The driver was carrying flight tickets to Spain's "Costa del Crime" and detectives believe he was travelling there to clinch a drugs deal.
The 32-year-old, who is originally from Drimnagh, lives in Co Kildare.
He was not arrested in the incident on Wednesday but an investigation has begun into the stash of cash.
A file on the seizure will now be prepared for the Director of Public Prosecutions.
The garda checkpoint was set up as part of Operation Hybrid, an initiative designed to provide an armed response to organised crime in the capital.
The driver is believed to be a key member of the mob controlled by jailed Brian Rattigan (37) and a well-known 35-year-old Drimnagh drugs trafficker who was busted with a large haul of cocaine in 2009.
"The fact that this particular individual had flight tickets to Spain on him indicates the money was to be taken out of the country," a senior garda source told the Herald.
"The man was not very happy at all when he was stopped. He has been regularly travelling back and forth to Spain.
"This is considered to be a very significant seizure against a serious crime gang."
Despite the fact that Brian Rattigan has been locked up since 2003, his associates remain one of the biggest targets of gardai. Last year, Rattigan won his appeal against his murder conviction of rival criminal Declan Gavin. The killing kicked off the bitter Crumlin/Drimnagh feud that claimed 17 lives.
Drimnagh criminal Rattigan remains behind bars where he is serving a 17-year sentence for organising a €1m heroin deal from the prison cell in Portlaoise Prison.
However, that sentence, which was imposed in March, 2013, was backdated to the time gardai made the massive heroin bust in June 2008.
Rattigan's murder conviction was a factor in the lengthy sentence for drug dealing which was imposed by the Special Criminal Court in 2013.
Senior sources fear that with his murder conviction now quashed, Rattigan will be entitled to go the Court of Appeal to get his sentence for the drugs offence reduced. Gardai believe he could be out of jail within months.
Rattigan still has a number of key supporters particularly in the south inner city, including two brutal brothers, one of whom was sentenced for being involved in a high-speed chase with gardai.
Rattigan's key bases are the James Street and Basin Street areas of the south inner city but also his home patch of Drimnagh where Wednesday's cash seizure took place.
The murder of Declan Gavin sparked what became known as the Crumlin/Drimnagh feud in which a further 16 men were killed.
After Gavin was stabbed to death, the gang feud resulted in the murder of nine people associated with Rattigan.