A teenager who racked up a £20,000 drug debt “ran for his life” after being stabbed in the chest, a court heard.

Mustafa Momand, 17, was stabbed with a “force so severe” that the knife broke through his breast bone and severed one of his pulmonary arteries.

He had been walking along Queen’s Road in Brighton when the defendant, 16, spotted him and stabbed him in the chest.

Brighton Youth Court heard that Mustafa, who knew the defendant, had racked up a £20,000 drug debt and feared being killed due to his outstanding debt.

The Argus: Forensic officers search near Gloucester Road after the incidentForensic officers search near Gloucester Road after the incident

Nathan Rasiah KC, prosecuting, said the attack was “most likely to do with animosity related to a drug debt”.

Witnesses saw him “spitting a large amount of blood” from his mouth as he ran away.

People from a nearby GP tried to perform first aid on Mustafa and doctors at the Royal Sussex County Hospital spent an hour performing emergency surgery to sew up his pulmonary artery.

Mr Rasiah said: "Mustafa managed to run for 150 meters before he staggered and collapsed. The blood from his wound was squirting out as he ran, leaving a trail on the ground, and witnesses saw him spitting a large amount of blood as he ran.

"The truth was that he had already killed him. Mustafa would and could never recover."

The Argus: Tributes left at the scene for Mustafa MomandTributes left at the scene for Mustafa Momand (Image: Sussex News and Pictures)

Mustafa's mother cried in court as details of her son’s death were read out.

The defendant, 16, who cannot be named for legal reasons, put the knife away and walked away when Mustafa collapsed, the court heard. He denies murder.

One person who witnessed the attack shouted to get his attention so they could take a picture of him.

The defendant shouted “take a photo and f****** arrest me, what are you going to do about it?',” said Mr Rasiah.

Jurors heard how Mustafa was described as a “cheeky chap” and “one of the lads” by his youth worker.

The Argus: The police cordon is Queen's Road, BrightonThe police cordon is Queen's Road, Brighton (Image: Andrew Gardner/The Argus)

On the day of his death, Mustafa had appeared at Brighton Magistrates’ Court for drug-related offences. He left court alone, while his youth worker was using the bathroom.

Mustafa was walking back up to Brighton Station at 4.50pm when he crossed paths with the defendant in Queen's Road and the attack happened.

He had originally moved to the UK from Afghanistan with his family in 2009 when he was three years old.

Mustafa's mother discovered cannabis in his room in November 2021. She suspected he was using and possibly dealing drugs, the court heard.

When Mustafa turned 16 in March 2022, things “got worse” and his behaviour changed, his parents found weapons in his pockets and he went missing for days on occasion, coming back with valuable items or injuries, the court heard.

Jurors were told in November 2022, Mustafa told his father he was in debt and needed £8,000 or “they will kill me”.

He was moved to social care in Bevendean in January 2023 and then up to South Croydon in April 2023 where his family felt he might be safer, the court heard.

Mr Rasiah said the defendant accepts that it was him and that he had a knife, but “denies having the necessary intent for murder”.

The teenager is also accused of two other separate incidents in July and August 2023 of threatening another with a bladed article and threatening with an offensive weapon, which he denies.

The trial continues.