The news of the death in Mountjoy has been confirmed by the Irish Prison Service.
Keith Lee, the man accused of the murder of his wife Joanne Lee last month, has been found dead in Mountjoy Prison.
He was found dead in his cell and foul play is not suspected.
The 40-year-old Keith Lee was separated from Joanne at the time her death; her body had been found in a wardrobe in Ranelagh last month, just days after her family had reported her missing.
Medics made efforts to resuscitate the 38-year-old after Gardaí found her unresponsive on 18 March, but Joanne Lee died at the scene.
