HM Prison Service
The most number of prisoners released due to error was 68 in 2009-10Darren Staples/Reuters

Hundreds of prisoners incarcerated for murders and other heinous crimes have been released early by mistake, data obtained from the Ministry of Justice has revealed. In the past decade 505 prisoners were released earlier than schedule.

The Ministry of Justice figures obtained by the Press Association showed that 41 prisoners and seven suspects in custody were wrongly released in England and in Wales in 2014-15. The most number of prisoners released in error was in 2009-10 when 68 inmates were set free.

"The first duty of the Prison Service should be protection of the public. These disturbing figures show that once a week the Prison Service release the wrong prisoner, and have done so for many years," Tory MP Philip Davies, a member of the Commons Justice committee, said. "This is nothing more than a shambles which puts the public unnecessarily at risk," he said. The Prison Service, however, maintained that such incidents are "very rare" and "releases in error are falling".

Lucy Hastings, director of charity Victim Support, said that many people who were victims of the prisoners will be "alarmed and frustrated" to know about their release. "We know it can be distressing and worrying when offenders are released from custody — releases made in error can make this many times worse," she said.

Shadow Justice Minister Andy Slaughter said: "This is a further sign of the crisis in our prisons where overcrowding and violence are rife."

In August 2014, prison authorities by mistake had released Martynas Kupstys out of HMP Lincoln while he was on remand for murder. He was rearrested after he was found at a nearby bus park. In July as well, a prisoner from HMP Hewell in Worcestershire was released after an apparent mix-up with another prisoner's surname. He was sent back to prison the following day.

"Public protection is our top priority. These incidents are very rare but we are not complacent. The number of releases in error have fallen by almost a third since 2009 [2010] and the vast majority are returned to custody very quickly," a prison service spokesman said. "The Prison Service investigates each incident and they are reported to the police for further action," the spokesperson said.