More than 320 prisoners have been wrongly released from jail over the past six years according to new figures released by the Ministry of Justice.

Among those released, are suspects awaiting trial for murder, armed robbers and those guilty of grievous bodily harm.

On average, more than one person is incorrectly released from custody due to a range of excuses - from prisoners getting mixed up with people sharing the same surname to others who saw court officials misfiling the sentence in custody records.

The number of prisoners wrongly released from prison over the past year is up by ten per cent

Martynas Kupstys, pictured here with his wife, was wrongly released from jail during his trial for the murder of Ivans Zdanovics who died in a house fire in Lincoln in January 2014. Kupstys stood at a bus stop for three hours deciding against trying to run away

Kupstys later told Lincoln Crown Court: 'I thought about running away. I thought about many things. I could go home, I could return to my friends, but I understood it cannot be that I was released. I should go to the court'

Kupstys, pictured here with a model of Adolf Hitler was later jailed for life for murder

Kupstys spent three hours waiting to be brought back to jail at this bus stop in Lincoln

Over the past 12 months, 71 people who should still be in custody have been wrongly granted their freedom - including two convicted of violence against the person and 17 for theft. Three robbers have also been released.

The number of those released in error has increased by almost ten per cent over the past 12 months

In previous years, seven sex offenders have been wrongly released along with 11 jailed for possessions of weapons.

In November 2016 Ralston Dodd, 26, from north London was jailed for nine years for grievous bodily harm after he stabbed Jerell Holland three times in back.

However, staff at Blackfriars Crown Court misheard the judge and wrote down nine months on the paperwork.

In June, Dodd's victim spotted his attacker wandering the streets prompting an investigation.

Dodd served seven months in HMP Thameside before his early release.

Kupstys, left, admitted in court he did not wish to run away as he was due in court, while Ralston Dodd, right, was wrongly released from jail serving seven months from a 9 year term

He was recaptured in Birmingham in July and returned to prison.

In September, Ben Rowland, 27, had been wrongly released from HMP Leicester after prison officials made an error calculating his sentence. He had spent a year behind bars having been convicted of two counts of assault. He also had time added for biting a prison officer.

He was told he must return to jail to serve an extra 35 days because of the original mistake.

The Ministry of Justice announced it had launched an investigation into how the error was made.

According to the MoJ, prisoners who are released in error are not considered to be unlawfully at large, unlike those who have escaped from custody.

Prisoners are said to be wrongly discharged if they have been released when they still have time to serve.

Number of prisoners incorrectly released between 2011 and 2017 2011/12 2012/13 2013/14 2014/15 2015/16 2016/17 ALL OFFENCES 42 44 50 49 64 71 Violence against the person 3 2 4 9 6 2 Sexual offences 2 1 0 2 2 0 Robbery 4 6 1 4 7 3 Theft offences 8 9 15 15 14 17 Criminal damage and arson 0 1 2 2 2 0 Drug offences 7 10 2 4 2 5 Possession of weapons 2 2 0 1 4 2 Public order offences 1 1 0 2 2 3 Miscellaneous crimes against society 5 1 6 5 7 4 Fraud offences 2 1 1 0 2 0 Summary non-motoring 6 6 5 4 6 8 Summary motoring 1 0 0 0 2 0 Offence not recorded 1 4 14 1 8 27 Source: Ministry for Justice

A spokesperson for the department said: 'They are not culpable and may be unaware that they have not completed their sentence or have outstanding warrants. Depending on the circumstances of the case, they may not be actively pursued for return to custody.'

Examples of mistakes behind erroneous releases include misplaced warrants for imprisonment or remand, recall notices not being acted on, sentence miscalculations or discharging the wrong person on escort.

Yet, in one case, Martynas Kupstys, who was on remand facing a murder charge in August 2014 was told he was free to leave HMP Lincoln. He stood for three hours at a nearby bus stop before he was recaptured.

He was later jailed for the murder of Ivans Zdanovics, 24, who died in a house fire in January 2014 during a retrial.

He told Lincoln Crown Court: 'I thought about running away. I thought about many things. I could go home, I could return to my friends, but I understood it cannot be that I was released. I should go to the court.

'I was released by mistake. I told them I was supposed to be at court. I was told everything was fine. I was told everything was in order and I was being released.'

When asked about his brief period of freedom, he replied: 'I enjoyed the sunshine for a few hours. I sat on the bench 20 or 30 metres from the prison gate. I thought that they had released me by mistake and they should come and get me and take me back in.

'I was out of the prison for about three hours. There came a time when the prison officers came and fetched me. Many prison officers.'

A prisoner from HMP Hewell in Worcestershire was released from jail on July 2014 after he was mixed up with another inmate who shared his surname. He was recaptured a day later.

Liberal Democrat chief whip Alistair Carmichael said: 'It is beyond belief that 71 potentially dangerous prisoners have been released by mistake.'

Rachel Almeida, of the charity Victim Support, said: 'Many victims will be shocked by these figures, especially if it involves perpetrators of serious crimes.'

The department claimed releases are rare but they work closely with police to recapture the offender.