The tax treatment of landlords is the main cause of the recent rise in residential rents, according to the Irish Property Owners' Association.
The group claims that that the costs for landlords have jumped by between 20-26%, which is putting a squeeze on the sector.
Information officer with the IPOA, Margaret McCormick, said that that landlords end up making very little profit on properties.
"Rents are rising because the cost of providing rental accommodation is rising," she said.
"Renters would be shocked to note that approximately 62% of the rent they're paying is going straight back to the Government in the form of income tax, USC, PRSI, and the local property tax.
"So for a landlord on a rent of €1,000 per month, the Government takes €620 of it, expenses take around €150, and the landlords keep €230.
"The tax treatment is what is causing the difficulties in this sector."