A murder probe has been launched after a huge illegal rave ended with a fatal knife attack in London.
Police said a 34-year-old was killed after being stabbed in the neck at an "unlicensed music event" In Lewisham on Sunday.
Cops have named the victim as Sean Williams, who had tried to break up an altercation at the 100 person gathering.
Williams was found in Lewisham, south London, with a stab wound in his neck.
Paramedics and police flocked to the scene, but Williams was pronounced dead.
A 37-year-old has since handed himself into police with a knife wound to his hand.
Police said the victim had attempted to break up a fight at the illegal rave.
A statement released by the Metropolitan Police said Williams had intervened and suffered a fatal stabbing to his neck.
Police have urged witnesses to "do the right thing" and offer any information they can.
A murder investigation was launched led by Detective Chief Inspector Kate Kieran, who said: “At this early stage we believe that both the victim and the suspect had attended an unlicensed music event at Culvery Road, SE6, during which, a fight broke out between two men.
"The victim intervened in this fight and suffered a fatal injury.
“I know there were around 100 people at the event and someone who was there knows the identity of the person responsible.
"I want these people to do the right thing and get in touch. I also urge the person responsible to hand themselves into police.”
Police have appealed for witnesses to come forward.
It comes after a five were injured at a separate attack in nearby Bexleyheath overnight.