A "well-liked and sociable" 20-year-old was murdered when a robbery went wrong, it has been alleged.

Tom Waugh was stabbed to death by a 17-year-old after he returned to a park in Tonbridge to try to help his friends escape.

But a jury at Maidstone Crown Court heard how he was stabbed with a Rambo hunting knife after he tried to distract the robbers.

The sound was caught on a doorbell camera and played to the jury as a 16-year-old went on trial also accused of helping carry out the killing.

It revealed a muffled conversation followed by a series of screams, which are believed to have come from Mr Waugh.

Prosecutor Nicholas Corsellis KC told how the victim called 999 but the call went silent after Mr Waugh collapsed near scaffolding in Avebury Avenue, Tonbridge.

He was discovered by a passer-by still clutching the phone, the court heard.

Mr Waugh's family drove to the scene, but he was pronounced dead as paramedics and his friend desperately fought to keep him alive.

The prosecutor said: "On August 19 last year, Tom Waugh was socialising with two friends in a park in Tonbridge.

"They were approached by two teenagers; at least one of them was armed with a large Rambo-style hunting knife.

"They then set about the friends but during the robbery Tom managed to run away but returned to try to rescue his friends.

"He picked up a stick to cause a distraction. The result was he was pursued by both teenagers intending to rob him of his telephone..but the robbery turned to retribution," he claimed.

Mr Corsellis alleged the 17-year-old – who was 16 at the time of the offence – plunged the knife between the eighth and ninth rib, severing the pulmonary artery and leaving Mr Waugh with an "unsaveable injury".

He added: "Despite that, Mr Waugh was able to call 999 and told the operator he had been stabbed and asked for help..they were the last words he would say and he died shortly afterwards."

The attackers then fled to a nearby house. They disguised their appearances, the knife was disposed of and efforts were made to destroy their clothes, it was claimed.

The 16-year-old has denied murder, robbery and attempted robbery and the mother of the 17-year-old – who admitted the killing at an earlier hearing – has denied assisting an offender.

Mr Corsellis claimed that the killer repeatedly called his mother after the stabbing.

Mr Corsellis said: "The reason, say the prosecution, could have only been for one reason – to tell her he was in serious trouble.

"She then drove her Mini car, between approximately 1am and 1.30am, from Croydon to her son's location, by which time Tom Waugh had been found and a murder investigation had begun."

He claimed a police cordon then prevented her from getting to her son until 7.15am and she then removed him from the area.

He added: "It is the prosecution's case that the 16-year-old knew his 17-year-old friend was in the habit of carrying a knife. In the days leading up to the incident, the two filmed themselves on their telephones with the murder weapon."

The family of the victim left court as the recording from the doorbell was twice played to the jury, who were then given a 15-minute break before the opening continued.

The teenagers cannot be named for legal reasons.

The trial continues.