The number of people being sent to prison for non-payment of fines has increased by more than 10%, according to the annual report of the Irish Prison Service.
More than 8,300 people were jailed last year for not paying fines, an increase of almost 800 on 2011.
Overall, the number of people jailed dropped slightly last year.
Over 17,000 people were jailed in 2012, slightly down on the previous year, the first decrease in five years.
It cost over €65,300 to keep a person in prison for a year, a slight increase on the year before.
Up to 23 people were jailed every day last year for not paying fines.
The report reveals that over 1,600 were women.
The number of people sentenced to less than three months in prison also increased by over 10%.
Call for consistency in use of community service
The Irish Penal Reform Trust has called for greater consistency in the use of community service orders by judges.
IPRT Director Liam Herrick said that judges in some areas are using community service orders rather than custodial sentences to deal with certain offenders.
Speaking on RTÉ's Morning Ireland, he said this contrasted with other judges in separate districts who were more likely to hand down custodial sentences to people convicted of the same offences.
Minister for Justice Alan Shatter recently said he favoured a greater use of community service orders than were currently being handed down by the judiciary.
The Prison Officers' Association last week complained that overcrowding had become a major problem in the Irish prison system.
Mr Herrick said that the tendency to send non-violent offenders to prison, such as those convicted of failing to pay fines, was causing a heavy administrative burden on the Irish penal system.
He said that Ireland was currently "at the very top of the EU scale" when it came to the number of people processed through Irish prisons on a per capita basis.
Mr Herrick said this was due to the use of short sentences for offenders.
The effect of this, he said, was that certain inmates, particularly those who failed to pay fines, were placed in prison for several hours before being released again.