Human remains believed to date from the 19th century have been uncovered by archaeologists on the site of the old Limerick Gaol near King John's Castle in Limerick city.
Some of the remains are believed to be those of prisoners who had been executed in the jail.
Limerick Gaol was constructed in 1813 and operated from then until 1904.
The remains, along with other artifacts, have been uncovered during archaeological works in advance of a flood relief project in the area.
The project is being undertaken by Limerick City and County Council in partnership with the Office of Public Works
In total, the skeletal remains of 36 individuals have been uncovered.
Other items discovered during the dig include an iron door believed to be from the prison and an iron grille placed in a drain leading from the prison to the Shannon.
This was believed to be designed to prevent a "Shawshank prison type prisoner escape from Limerick Gaol", according to senior Archaeologist Ian Russell of Archaeological Consultancy Services Unit, who are working on the site.
Mr Russell said that while they were expecting to uncover some remains, the total number of 36 was somewhat of a surprise.
He said that the skeletal remains have now been removed for further analysis.
"Those remains will now be examined by our senior osteoarchaeologist in order to try and determine their sex, age and pathology to shed some light on the type of life they may have had and how they died.
"We will also try and identity the remains if it will be possible," Mr Russell said.
He said that some of the remains may be those of prisoners from the jail as copper buttons believed to be from the uniforms have also been found.
Historian with Limerick Museum John Elliott said that there is at least one historical account of an execution and subsequent burial on the site of the old jail.
He said that there were historical reports from 1813 of plans to construct a drop-door and gallows near the jail on Merchant’s Quay.
"Mary Cooney was executed having been found guilty of murdering her former employer in Limerick in 1837.
"Her obituary report states that she was brought to Gallows Green, about 2 miles outside Limerick, to be executed.
"The report states that her remains were then brought back to the city jail by the military and buried within the walls of the jail.
"So we know that definitely some people who were executed were brought back to the prison to be buried," Mr Elliott said.
He added that a hospital also operated on the site in the 19th century, and that some people from the hospital may have been buried on the grounds.
The remains and any other artifacts are to be given to the National Museum.
The archaeological works in advance of the commencement of the flood relief scheme are continuing in Limerick.
