Derek Dunne's violent death at his home in a suburb of Amsterdam at the weekend may have major repercussions for other Irish criminals based in the Netherlands. For Dunne's mentor, protector and father-in-law is George "The Penguin" Mitchell, possibly the Republic's richest criminal.
Mitchell's drug-dealing and robbery had helped him amass a considerable fortune by 1996 when he chose to exile himself from Ireland after another Dublin gang killed the journalist Veronica Guerin. The State's response to Ms Guerin's murder was to set up the Criminal Assets Bureau (CAB), which could seize virtually every penny Mitchell had made from crime.
Furious with the gang that had killed Ms Guerin and prompted the war against organized crime, Mitchell left for Amsterdam where he had built up relationships with Dutch drug-suppliers.
His departure followed that of his son-in-law, who had left Dublin after a dispute with another of the city's criminal gangs. Dunne had attacked and beaten up the nephew of a former north inner-city criminal, Gerry Hutch, in 1994. An attempt was made on Dunne's life and he left for Liverpool.
The Garda operation against Dunne continued across the Irish Sea, and in conjunction with Merseyside police he was arrested and charged with heroin-trafficking in 1996. The evidence offered in the case was not strong enough to convict him.
After his acquittal he left Britain and went into business with his father-in-law, by then establishing his criminal enterprises in the Netherlands. Dunne had made a substantial amount of money from heroin-dealing in the north inner city, where he had grown up.
He had forsaken a promising career as a soccer player with St Patrick's Athletic to deal heroin around a neighbourhood, which by then was on the verge of being destroyed by the drug. It is understood he escaped with most of his wealth despite having some of his property seized by the CAB in one of its first operations.
Since moving to Amsterdam, Dunne had become possibly the biggest heroin-supplier to Dublin's 14,000 addicts. Gardai say virtually all heroin arriving in the city comes from Amsterdam. Most of it came from Dunne, who did not deal in other drugs in order to avoid conflict with other drug-suppliers.
It is thought the division of the drug supply among Irish traffickers has come about through negotiation. It is also thought likely that only a figure with the authority in the criminal world of Dunne's father-in-law, George Mitchell, could have organised such a contract with other powerful and dangerous figures.
Dunne's heroin-dealing niche was lucrative, although it is known his operations had been hit by Garda and Dutch anti-drugs police operations in the past year.
The origin of the dispute which led to his killing was unclear yesterday, but it has struck at the heart of Mitchell's operations. Mitchell is a close associate of two other successful Dublin criminals, who had been based in Amsterdam for years before his arrival.
These two men, who had both been associated with the highly-volatile republican group, the Irish National Liberation Army (INLA), are reported to have built up fortunes through the drugs trade. One has close links to the Russian mafia.
Mitchell was released from prison in the Netherlands last year after serving two years for hijacking a lorry containing £4 million worth of computer parts. His position in the world of organised crime is under threat as a result of this attack on his son-in-law.
Dunne's death at 27 is indicative of the risks involved in a trade where there is increasingly violent competition for the huge spoils available.
He is also one of the last of a group of drug dealers from Dublin who built up careers in the early and mid-1990s before moving abroad.
A close associate of Dunne's during his heroin-dealing career in Dublin was Thomas "The Boxer" Mullen. Mullen ran a neighbourhood heroin ring from his flat in Dominick Street, a short distance from Dunne's old home in Portland Place.
Like Dunne, Mullen had a promising sports career and was rated sufficiently good as an amateur boxer to have gone on to a professional career had he not chosen to be a drug-dealer.
Mullen established a substantial business and was able to buy a vacant site off Clonliffe Road and build his own, lavishly decorated, house.
He decided to move away from Dublin and become an offshore supplier of heroin to his home town after he was named in the Dail by the local Independent TD, Mr Tony Gregory, and local anti-drugs activists began to agitate against him. A thousand people marched to his home in December 1996, led by a group carrying a white coffin to signify the deaths caused by his trade.
Mullen was arrested with a sizeable amount of heroin in Manchester a year later and is serving an 18-year prison term.
Another former associate, Sean Comerford, is serving 12 years after he, too, was arrested with a large consignment of heroin at his house in Manchester in November 1998. Comerford had also been forced to leave Dublin in the mid-1990s because of pressure from the CAB and fear of attack by vigilantes. It is believed that when he set up his new base in Manchester he received drugs from Dunne in Amsterdam.
Two other of Dunne's associates were reputed to have been in his house in the Amsterdam suburb of Slotervaart when he was shot. One worked closely with Dunne, testing the heroin for purity and managing the business side of the operation.
The other had been a member of the gang which killed Veronica Guerin and had known Dunne since his days as an ecstasy dealer in Dublin in the early 1990s. Their whereabouts were not known yesterday.