Lawyers for a teenage boy who is in solitary confinement at Oberstown youth detention centre claim he is being denied his constitutional and human rights.
The 17-year-old was separated from the other detainees following an incident during industrial action at the Dublin facility.
On August 29, a fire broke out at the centre. Earlier in the day, a number of young offenders made their way onto the roof during a strike by workers.
The boy at the centre of today's court action was put into solitary confinement shortly afterwards.
Sean Gillane, who is representing the 17-year-old, claims he was denied reading and writing materials, had no access to his family and was served his food through a hatch during what was effectively a 24-hour lockdown.
During a consultation with his solicitor, the court heard the boy was dressed only in blue shorts and socks.
Mr Justice Anthony Barr was told he was not subjected to any sort of disciplinary process and was being treated worse than an adult prisoner would be treated.
Mr Gillane claims his constitutional rights were breached as well as his rights under the European Convention on Human Rights.
He is also seeking damages and was given permission to pursue his reliefs through a judicial review.
The case will return to the court tomorrow.