Evidence given by a boy accused of murdering teenage Mustafa Momand has been branded “a tissue of lies”.

The jury at Brighton Youth Court today heard summaries of the case from Nathan Rasiah KC, prosecuting, and Balraj Bhatia, defending.

The defendant, 16, who cannot be named due to his age, denies murdering Mustafa, 17, in Queen’s Road, Brighton, on October 5 last year. 

The boy caught the train from Southwick to Brighton while carrying a balaclava, a pair of gloves and a knife and was wearing three pairs of trousers. He said while giving evidence earlier in the trial that the balaclava was to hide acne on his face.

He told the jury he took the knife with him to self-harm, not to hurt anyone. He also said he was "off his head" on drugs from the night before.

Mustafa “ran for his life” after a kitchen knife was “plunged” 9cm into his chest and severed one of his pulmonary arteries. He died in hospital shortly after.

The Argus: Mustafa Momand running past Tesco in Queen's Road, BrightonMustafa Momand running past Tesco in Queen's Road, Brighton (Image: Sussex Police)

The defendant claimed Mustafa had been threatening to stab him so he got his knife out to “scare him” and the older boy ran into it.

Mr Rasiah told the jury the defendant’s evidence was a “tissue of lies”.

“He went to Brighton and stabbed Mustafa Momand intentionally. It was not an accident, it was not self-defence. It was a clear a case of murder as you could want,” said Mr Rasiah.

The court heard Mustafa was scared to be in the city due to a £20,000 drug debt to Zakaria Deghayes, also known as Gotti or Zico.

Mr Rasiah said: “It was not just a journey on the train. The defendant came prepared for the stabbing with gloves, a balaclava, trousers and a knife. We don’t have the knife because he hid it and has not revealed the location.

The Argus: Mustafa Momand died in hospital on October 5Mustafa Momand died in hospital on October 5 (Image: Supplied)

“Why did you say ‘I’m going to f*** you up. I’m going to f***ing get you’? ‘I was off my head’. An intoxicated intent is still an intent. The evidence makes it clear that he knew what he was doing.

“Why sprint after a fearful Mustafa if he was defending himself, stopping only when Momand collapsed? You will come to the conclusion that his account to you was utterly hopeless. A tissue of lies.”

Mr Bhatia told the jury: "We submit to you that this is a tragic accident."

The Argus: Flowers and tributes for Mustafa MomandFlowers and tributes for Mustafa Momand (Image: Sussex News and Pictures)

He said the boy could not have known where Mustafa was in order to carry out the attack.

READ MORE: Boy who stabbed teenager in Brighton said he 'skipped into knife'

He said: “What possible evidence have we been given that shows us he knew where Mustafa was going to be?

“You need to look at the witnesses and decide if they are truthful. Use your ability. You have to make the most difficult decision you will ever have to make.”

The jury retired to consider their verdict.