The Minister for Justice Frances Fitzgerald has announced the closure of a section of Mountjoy jail used to house 'protected prisoners'.
The Separation Unit was described as overcrowded and dirty by authorities including the Inspector of Prisons.
Judge Michael Reilly's report suggested the area had been forgotten in the overall refurbishment of the campus.
During his visits over a six month period, Judge Reilly said the so-called 'protected prisoners' were bored and spent most of their time on lock down.
Confirming the closure of the unit today Minister Fitzgerald said a phased shut down began in July with the final inmates relocated last Friday.