A 17-year-old from Dagenham is facing jail after pleading guilty to brutal knife attack that led his teenage victim to have his leg amputated.

The defendant, who cannot be named due to his age, admitted unlawfully and maliciously wounding another teenage boy with intent to do grievous bodily harm at Snaresbrook Crown Court today.

The stabbing, described by the judge as a “grave offence”, took place in Blackborne Road, Dagenham, on June 23 this year.

The victim, who is now aged 18, lost his right leg and was in intensive care for four weeks due to the extent of his injuries after being knifed in the groin.

Judge Oscar Del Fabbro said CCTV footage showing the 17-year-old’s movements after the knife attack had raised questions about the “defendant’s attitude and personal remorse”.

He said: “It suggests a degree of indifference and worryingly a degree of assuredness in changing his top, getting rid of the weapon, which has never been recovered, these are all matters that trouble me enormously.”

Defence barrister, Laurie-Anne Power, said the teenager “did not for a moment want the extent of injuries that had occurred to be caused”.

She said: “The bravado and showing off afterwards, the swerving motion I think your honour is referring to.”

But the judge interjected saying: “It’s not only that, it’s his demeanour and conduct, it’s worrying.”

As he set a date for sentencing, the judge said he required further reports to address issues such as “the risk that this young man poses in the future”.

But he acknowledged the 17-year-old was of “previous good character and had not offended before”.

The accused admitted one count of having an offensive weapon and one of wounding with intent as the trial was due to begin.

He will be sentenced on December 5.

Defence barrister Ms Power said delays on two separate days in bringing the defendant to court from custody had been “totally unsatisfactory” and had made “a distressing situation even more distressing”.

The judge said the situation was “extraordinary” and he would be making further inquiries of the prison service as to why it had happened.