Four men who were arrested as part of an investigation into an alleged assault at the Midlands Prison in Portlaoise have been released without charge.
The individuals, who are aged in their 20s and 30s, were returned to the facility in Co Laois.
Gardaí say they are investigating all the circumstances of an incident, which is alleged to have taken place in the Midlands Prison last Saturday.
The arrests were made today by gardaí from the Serious Crime Unit of the Laois/Offaly Garda Division who are investigating an assault causing harm.
