Middle class drug users are the biggest source of income for organised crime gangs, according to Mountjoy Prison governor Eddie Mullins.
Mullins, who has worked within the Irish Prison Service for 33 years, also serves as Independent Chair on the Local Policing Forum in Clondalkin.
"Gangland thrives off middle class people who have the means to pay for drugs. It is the primary source of funding," Mullins told Katie Hannon in an in-depth interview on the latest episode of Upfront: The Podcast which will be available here from Tuesday morning.
"It's not only contributing. It is probably the biggest factor because the money that we're talking about is in the millions.
"The people that I work with here in the prison service don't have millions. They certainly don't have the means to support the lifestyle of the wealthy drug barons and the wealthy people who control the drug trade.

Despite his assessment on how much money middle class people are spending on drugs on a week-to-week basis, Mullins estimates that most Irish prisoners come from marginalised communities.
"At least 70% of the prison population have drug use or addiction issues. 70% have mental health issues, 80% never did the Leaving Cert and about 80% finished school before the age of 15.
"98% of the prisoner population come from communities of disadvantage. It's not a new phenomenon. The majority of people in prison are people who have come from poverty, from deprivation, from marginalisation and a lack of opportunities."

Overcrowding is a major challenge facing the Irish Prison Service with over 60 prisoners doubling up in Mountjoy and forced to share cells designed for one person.
"The prison population is predicted to grow by another 600 between now and the end of the year. We will always accommodate people because we're obliged to do so. But it will mean that more prisoners will be sharing cells and we have to put both beds in [single] cells and that again adds to the tension."
Mullins believes reform of Irish drugs laws is one possible solution to overcrowding concerns.
"The majority of people in prison who are in prison are here because of poverty and because of addiction. And prison is not the right place for them. Prison is a school for criminal behaviour.
"I think we need to be very brave and courageous. I think decriminalising drug use, I think we have to go down that route.
"I'm talking about the average Joe who ends up in prison for 12 months or 18 months for intent to supply and possession. I think we need to take imprisonment out of the equation for an awful lot of the people who I deal with because they're not making serious money out of drugs.
"If they had a system of accessing the HSE and community support agencies, they would certainly be better served than sending them up into Mountjoy Prison."
The full interview with Eddie Mullins is available as a podcast here or wherever you get your podcasts.