The State may have to pay out nearly €333m over nine mass action personal injury claims, including those being taken by prisoners forced to slop-out.
The 2019 annual report of the State Claims Agency (SCA) shows the total potential liability from all claims soared by €480m from €3.15bn at the start of last year to €3.63bn at the end.
Last December, the SCA was dealing with 11,580 active claims, of which 2,472 (21pc) related to mass actions.
The majority of the claims - 1,562 - related to the lack of in-cell sanitation and were taken by former and current prisoners against the Irish Prison Service (IPS).
The Supreme Court found last November that the plaintiff in the lead case, Gary Simpson, should be paid €7,500 compensation.
It ruled that having to use a bucket as a toilet and empty it each morning for nearly eight months in 2013 in Mountjoy Prison was a violation of his constitutional rights.
The SCA said that arising from the judgment, it has devised a scheme of settlement under which offers of damages and legal costs are being made to qualifying plaintiffs.
Sixty-six in-cell sanitation claims were resolved last year and 84 new ones lodged.
Other mass actions come under the heading "Prison-based TB" and involve 23 active claims.
The figures show that estimated liability from "catastrophic injury clinical claims" make up the bulk of the estimated liability, and increased last year by €268m, from €1.7bn to €1.97bn.
The €1.97bn made up 54.5pc of the overall potential €3.63bn for the year.
The potential liability from "other clinical claims" totalled €745.6m, while that from general claims climbed by €89m (11pc) from €820.8m to €909.8m at the end of last year.
The report said the estimated outstanding liability associated with active catastrophic injury claims has increased by 105pc over the period 2015 to 2019.
Due to the high value of catastrophic injury claims, it is the principal driver of the overall estimated outstanding liability.
The number of active catastrophic injury claims increased by 42pc from 2015 to 2019 from 214 to 304.
Such claims can take some time to resolve because of their complexity, in particular the number of independent expert reports needed.
The estimated outstanding liability associated with other clinical claims has increased by 93pc from 2015 to 2019, despite a much smaller rise in the number of active claims of 10pc from 2,786 to 3,066.
The report said the increase is primarily driven by claims in the €100,000 to €500,000 estimated liability range.
Last year, the SCA resolved 2,704 claims and received 3,516 new ones.
The cost of resolving and managing all ongoing active claims for the SCA last year totalled €416.9m, which was an increase of 20pc on the 2018 total of €347.1m.
The costs last year were made up of settlements of €307.3m and legal and other costs of €109.6m.
Clinical settlements accounted for €251.7m of agreements and €73.5m of legal and other costs.