Ten prisoners are being treated for suspected overdoses at Portlaoise Prison.
One of the men is “clinging to life” in a critical condition in hospital while the condition of the other inmates is described as “serious”.
The incidents happened this afternoon on the C wing of the midlands prison, which houses a number of convicted killers and gangland criminals.
One of the prisoners hospitalised after overdosing is a gangland criminal in his 40s who is serving a life sentence for murder.
From Dublin’s south inner city, he was convicted for his role in a gun murder in 2009.
He was one of the first six prisoners hospitalised this afternoon.
The drug used has still not been identified but it is understood to be a powder substance.
It was discovered in at least one cell in a series of searches that took place after the prisoners became ill.
It is understood that inmates who consumed the drug thought it was Spice – a synthetic version of cannabis.
However, they are suspected to have ingested a far more potent substance.
Six inmates were initially brought to hospital while a further four were hospitalised later this afternoon.
Prison sources say that the illicit drugs have been “retrieved” from the C wing and have been sent for testing.
Portlaoise is Ireland’s highest security prison.
In a statement the Irish Prison Service said it is working closely with the HSE and it has secured extra naloxone kits in the event of clinical intervention.
“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 contraband.
“The Irish Prison Service is committed to preventing the access of contraband including drugs into prisons and continues to be a high priority for the Irish Prison Service. The Irish Prison Service has committed to continuing to invest in new technologies and measures to support our efforts to keep contraband out of prisons.”
It said prison staff have increased the use of “random and intelligence led cell searches on a daily basis”.
“Our Canine Unit carry out searches around the prisons, including a greater focus on searching deliveries into prisons.
“The Irish Prison Service continues to engage with An Garda Síochána with regard to preventing contraband entering our prison and this happens at both local and national level. The Operational Support Group work closely with their colleagues in An Garda Síochána on a regular basis and the sharing of intelligence has led to target searches resulting in the seizure of contraband.
“The Irish Prison Service are committed to strengthening our measures in keeping drugs out of prison and in this regard a new drug strategy was published last November.”
Last month the Irish Prison Service issued an urgent drug alert to all prisons after an analysis by the HSE’s National Drug Treatment Centre confirmed the presence of a nitazene-type substance called N-Pyrrolidino protonitazene – which has been associated with the overdoses in custody.
It is a very strong and potentially deadly synthetic opioid and has been appearing across the country since June.
The tablets often come in blister packs and are often yellow in colour. People could easily mistake them for benzodiazepines.
However, the nitazine tablets do not contain benzodiazepine and are unsafe to use. Nitazine is a synthetic opioid.
The Irish Prison Service sent a protonitazene tablet to the HSE lab after they had an overdose in one jail.
The lab found it was the same type as the one they had begun to see in Ireland since June.