An “extremely dangerous” prisoner who stabbed a man three times in the back in Islington is being hunted by police – after a clerical error meant he was released from jail months into a nine-year sentence.

Ralston Dodd, 25, who lived in Britannia Row off Essex Road, was jailed in November last year after he admitted the attack on a 21-year-old man following an argument in Laycock Street, off Upper Street.

The attack, described as an “appalling act of violence” by police, left the victim fighting for his life and a manhunt was launched to track Dodd down.

Now police have been forced to launch a second search for the violent offender, after he was released from prison in error as a result of a court incorrectly recording his sentence.

The Ministry of Justice said it was urgently investigating the incident and a warrant for Dodd’s arrest has been issued.

He was arrested on October 11 and was sentenced to nine years’ imprisonment at Blackfriars Crown Court on November 11 after pleading guilty to causing grievous bodily harm with intent.

At the time Det Insp Will Lexton-Jones said: “[The investigation has] ultimately led to an extremely dangerous offender being jailed. This was an appalling act of violence that almost cost a man his life. The seriousness of this offence is reflected in the extensive prison sentence.”

Dodd was said to have been held in custody at HMP Thameside in south-east London before his release.

An Ministry of Justice spokeswoman said such releases in error are “extremely rare but we take any case very seriously”.

“We are urgently investigating so we learn the lessons to prevent it happening again,” she said. “Public protection is our priority. A warrant has been issued and police are pursuing the offender.”

A Scotland Yard spokesman said officers in Islington wished to trace a man “for being unlawfully at large” and a warrant was obtained at Blackfriars Crown Court on June 23. Anyone who may know Dodd’s whereabouts is asked to call Islington Police on 101.

Reporting by Press Association