A total of 46 inmates were accidentally released from prison in England and Wales in the year to March 2021, according to new figures from Her Majesty’s Prison and Probation Service (HMPPS).
Two of the prisoners released by mistake had been jailed for violent offences, one for a sexual offence, and 10 for theft.
The figure represents a decrease of 8% on the year ending March 2020, when 50 inmates were released in error.
The highest figure in recent years was in 2017, when 72 prisoners were released by accident.
HMPPS said there were five escapes from custody in the past year, with one of those still at large 30 days after their escape.
The previous year saw 16 inmates escape, with eight of those recaptured within 30 days of going missing.
There has also been a decrease in the number of prisoners absconding – an escape from places like open prisons – from 143 in the previous 12 months to 101 in the latest period.
Out of those, 34% remained at large after 30 days, down from the 42% in the previous year.
There were 87 Release on Temporary Licence (ROTL) failures – where a prisoner fails to stick to the conditions of their temporary release – in the year to March 2021, a decrease of 87% from the year up to March 2020.
HMPPS said that the majority of escapees are quickly re-captured before being charged and prosecuted.
Prisoners are usually re-categorised on their return to prison and may be moved to a higher security establishment.
The figures come after the early prison release scheme that was put in place last year to help jails deal with COVID was paused after six inmates were freed by mistake.
The government early release scheme was designed to avoid thousands of often cell-sharing inmates becoming infected with COVID.
Coronavirus cases were confirmed in half of the prisons in England and Wales at the beginning of the pandemic, though the true figure is likely to be far higher due to limited testing.
Stronger processes were put in place by the Prison Service after the prisoners were let out of two open prisons in Gloucestershire and Derbyshire, and a young offenders institution in south-east London.
The men later "returned compliantly to prison when asked to do so”, officials said.
The Prison Service said the releases were down to "human error”.
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