Six-year high for number of inmates freed by mistake
The number of prisoners mistakenly released has reached the highest level for six years.
Sixty-five convicted criminals or suspects were freed in error in 2015/16 - an increase of 16 compared with the previous year and the highest in any financial year since 2009/10, when there were 68.
A prisoner is officially classed as having been released in error if they are wrongly discharged from an establishment or court when they should have remained in custody and when they had no intention to escape.
The Ministry of Justice said examples can include misplaced warrants for imprisonment or remand, recall notices not acted upon, sentence "miscalculation" or "discharging the wrong person on escort".
It came as a rash of official data sparked fresh concerns about safety in prisons in England and Wales.
Assaults on prison staff are at record levels, with 15 attacks every day. In the year to the end of March there were 5,423 assaults on officers - up 40% on the previous year. The tally included 646 serious incidents.
The overall assault count was up by almost a third to more than 22,000, while in the 12 months to the end of June there were 105 apparent self-inflicted deaths - up from 82.