THE trial of a teenager who stabbed a lad in the groin during an organised gang fight has collapsed after he pleaded guilty to a lesser offence.

It had been alleged that the 17-year-old produced a knife during a fight in a park, which had been arranged on Facebook, and stabbed his victim in the privates.

But on the morning of the third day of his trial at Swindon Crown Court for wounding with intent he indicated he would plead guilty to affray.

And after prosecutors added the charge to the indictment he pleaded guilty to it and the judge discharged the jury from reaching verdicts on the assault allegations.

The maximum penalty for affray is a three years whereas wounding with intent to cause grievous bodily harm can carry life and unlawful wounding up to five years.

Marcus Davey, defending, said his client pleaded guilty to the public order offence on the basis he did not use a knife to cause the injury.

"It was on the basis he caused an injury. The Crown will not say it was with a knife," he said.

"He was 16 at the time and is not to be sentenced on the basis it was a knife: be it a key or glass he used."

Judge Douglas Field adjourned the case to Thursday May 8 so a pre-sentence report can be prepared and released the teenager on bail until then.

He was told the lad, who was living in The Lawns area at the time of the offence, had now moved out of the area to Richmond in Surrey.

The jury had been told he was in a gang called the North Young Guns who operated near the Orbital Shopping Centre in north Swindon.

One of the group had been accused of taunting some other teenagers on Facebook and the victim said they had decided to stand up to them.

A fight was arranged for Wednesday March 6 last year and the victim went with friends from college and a local football team to the area outside Asda Wal-Mart.

From there they went to a children's play area called the Blue Park, in nearby Haydon End, where the North Young Guns, or NYG, were waiting.

Minutes before the fight one of the victim's group said he received a voicemail message from the defendant threatening to shank him, meaning stab him, in the groin.

Rob Welling, prosecuting, told the court he said 'I'm going to shank you, innit, I'm going to cut off your little b******s, innit. Come on, North Guns all day'.

Both gangs said they were outnumbered by the other group and as a result of the violence the defendant, who also received a severe beating, stabbed the victim.

He claimed he had used a piece of glass he picked up from a bottle which had been smashed over his head and was acting in self defence.

The victim and his friends said they saw a knife and any beating was meted out after the stabbing, not before.

An incident then took place at the Great Western Hospital where victim and defendant had both been taken for treatment to their respective injuries.

Words were exchanged between the victim and the mother and brother of the defendant.