A man who stabbed a teenager to death in an Ilford street fight in 2005 has had his sentence reduced for good behaviour in prison.

Rehan Asghar, of Balfour Road, was sentenced to a minimum of 12 years in 2007 for the killing of 16-year-old Kashif Mahmood in a subway under Winston Way.

The boys had arranged a street fight between Riches Road and Richmond Road and friends gathered to watch.

But when Asghar started losing the fight, he pulled a knife from his sleeve and stabbed unarmed Kashif seven times.

The younger boy, of Goodmayes Lane, died after the blade penetrated his heart, aorta and liver.

But on Thursday, High Court judge Mr Justice Silber said Asghar’s conduct in jail had been so “exceptional and unforeseen” that he deserved an 18-month cut to his minimum term.

The judge said Asghar had “put himself at risk” during a riot at Bullingdon Prison when he came to the aid of an asthma sufferer and took him to a place of safety.

“He further assisted negotiations when the instigators of the riots tried to get others involved with threats”, he added.

Vaunted as “helpful and enthusiastic” and “an exceptional role model” to other prisoners, Asghar had written an open letter to the”’youths and teens of east London” explaining his experiences of prison and warning others of the consequences of committing crime.

The judge concluded: “All the information that has been supplied to me in Rehan Asghar’s dossier satisfies me that he has made exceptional and unforeseen progress”.

The ruling means that Asghar can ask to be freed on parole in 2016.

When released, he will spend the rest of his life on licence and face recall to prison if he puts a foot wrong ever again.