Dozens of prisoners convicted of breaching restraining orders were mistakenly released from prison early, the Ministry of Justice has confirmed.

It said 37 offenders were wrongly let out in recent weeks under a government scheme designed to reduce overcrowding, indicating the error was down to their offence being logged incorrectly.

The Ministry of Justice (MoJ) said the majority had now been returned to prison and police are working “urgently” to locate the rest.

Former chief inspector of prisons Nick Hardwick said the incident would be “very distressing and frightening for the victims”.

He told BBC Radio 4’s Today programme it appeared to be “a policy error rather than an operational error”, and the likely issue was that the older piece of legislation the men were convicted under was not identified as a red flag.

The MoJ confirmed 32 of those released early are now back in prison but five are still being searched for.

It also suggested the issue had been fixed for forthcoming early releases and all victims had now been contacted.

Under the early release policy, which went into effect earlier this month, some inmates have been released after serving 40% of their sentence, instead of 50% – a policy the government says is needed because the prison system is “broken”.

Offenders who were jailed for breaching restraining orders were supposed to be excluded from the early release scheme as part of a wider effort to ensure domestic abusers did not end up back in the community early.

A spokesperson for the MoJ said the department was committed to keeping “the most dangerous offenders locked up”.

A statement continued: “We are working with the police to urgently return a very small number of offenders – who were charged incorrectly and sentenced under repealed legislation – to custody.

“The convictions remain valid with offenders monitored since their release and will soon be back behind bars.”