Three separate investigations are under way into the circumstances surrounding the death of a prisoner in Cloverhill Prison in Dublin last night.
Marius Sarzynski was found slumped in his cell by prison staff at around 10.30pm. He had been charged with murdering his wife in September 2013.
Medical staff were alerted and an ambulance was called. He was removed to Tallaght Hospital where he was pronounced dead.
It is believed gardaí were at the scene shortly after the incident and were back at the prison earlier today to carry out an investigation into the circumstances of the death.
Foul play is not suspected but Mr Sarzynski's death is not believed to be due to natural causes.
A spokesperson for the Prison Service confirmed an investigation had commenced following the death of the prisoner.
As well as the garda inquiry, the Inspector of Prisons and the Prison Service will both carry out separate investigations.
The Inspector of Prisons will then give its report on the death to the Minister for Justice.
It is believed Mr Sarzynski had just been returned to prison after receiving hospital treatment, after jumping out the window of a courthouse.
He had been charged with the murder of his wife Aleksandra Sarzynski, who died in an apartment in Bective House in Beaufort Place, Navan, Co Meath in August 2013.