An average of 39 inmates were sleeping on temporary mattresses in Irish prisons each night last year.
New provisional figures provided by the Irish Prison Service shows that an average of three prisoners in Limerick Women's Prison slept on mattresses each night throughout 2022, while an average of 36 others were on mattresses nightly in the rest of the prison system.
The figures have emerged as provisional data shows there were 7,055 committals last year involving 5,810 people - far more than the comparable figures for 2021.
The number of committals reached its highest annual level since 2019 last year, although as recently as 2015, there were more than 17,000 committals involving more than 14,000 people.
However, there were 4,245 people in Irish prisons at the end of December - a higher number than in any of the previous four years.
Overcrowding at the women's prison in Limerick has been criticised by Keith Adams, penal policy advocate in the Jesuit Centre for Faith and Justice, who late last year said the proposed redevelopment of the facility - in which 22 additional cells will be provided - may not fully compensate for the current high numbers of inmates there.
Last week Prison Officers Association General Secretary Karl Dalton said four prisons had exceeded capacity and that overcrowding increased the risk of violence.
Mr Dalton told Newstalk: "It’s been happening constantly and is going to be the future as far as we can see when you watch numbers and you look at the daily figures going up and up.
“We know what’s happening in the courts [and] with no sign of any new accommodation it’s just unacceptable."
The Irish Prison Service said it has no control over the numbers committed to custody at any given time and that the system was "subject to peaks and troughs".
A spokesperson said the return to a more normal level of Court activity following the lifting of Covid restrictions had led to an increase in committal numbers.
"Where the number of prisoners exceeds the maximum capacity in any prison, Prison Service officials make every effort to deal with this through a combination of inter-prison transfers and structured Temporary Release," the spokesperson said.
"Decisions in relation to temporary release are considered on a case by case basis and the safety of the public is paramount when those decisions are made."
The IPS said the new accommodation in Limerick is expected to become operational in the first quarter of this year and the spokesperson said: "We are also taking a number of short and medium term steps to address the issue of increasing prison numbers."
The Department of Justice recently published the Review of Policy Options for Prison and Penal Reform 2022-2024 and the IPS said those proposals are intended "to strengthen the options available to judges when they are considering cases, to facilitate the effective and efficient use of community sanctions by the courts, and to ensure that the courts have a wide range of appropriate options for dealing with people who have committed minor offences".
A new Irish Prison Service Capital Strategy 2023 is also being developed.