Large numbers of inmates in Irish prisons reportedly have a history of homelessness, drug addiction and psychological problems.

Reports this morning said new research had found that one-quarter of inmates were homeless at the time of their committal to prison, while more than half had been homeless at some stage in their lives.

Of those who were homeless on committal, one-third had been previously diagnosed with a mental illness and two-thirds had spent time in a psychiatric hospital.

90% were also found to be drug users, with the majority reporting serious addiction problems.

The research, which was commissioned by the Probation and Welfare Service, also showed that petty repeat offenders and not serious criminals make up a significant portion of the prison population.