Analysis by the HSE National Drug Treatment Centre Laboratory has confirmed the presence of a “nitazene-type substance” associated with overdoses in Irish prisons, one of which is fatal.

In a statement, the prison service said it is “working closely with the HSE in response to this detection of nitazene”.

“Prison healthcare teams have adequate stocks of naloxone should clinical intervention be required,” it said.

“Extra vigilance is being taken across the prison estate and the Irish Prison Service has commenced an information campaign for prisoners around the dangers of consuming non prescribed illegal drugs.”