Inquests haven't taken place in over half of the cases.
100 prisoners have died in Irish jails over the past 10 and a half years.
According to freedom of information figures, they passed away between 2012 and last month.
15 have been confirmed as suicides - while the inquests haven't taken place in over half of the cases.
Former governor of Mountjoy and Portlaoise Prison, John Lonergan, says the number of deaths in custody is concerning:
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