A 16-year-old boy stabbed to death outside a birthday party in Croydon, south London, on Sunday morning, has been named as Wesley Sterling.
The boy was initially not thought to have been a guest at the party, which was held at Croydon Sports Arena, but police have now confirmed he was.
A post-mortem found the cause of death to be a single stab wound to the chest.
A 15-year-old boy was arrested in connection with the investigation but has been released on bail until June.
Officers were called to the venue in Albert Road at 0018 BST on Sunday, following reports of a disturbance outside.
A police spokesman said: “On arrival they found a youth in a walkway near the club with serious chest wounds.”
He was pronounced dead at the scene.
The spokesman said there had been another incident at the same place at about 2300 BST, when between six and eight people had tried to gatecrash the party.
Det Insp Alison Hepworth said: “We know there were many guests at the party and would appeal to them to come forward with information on what happened.”
Anyone with any information about the stabbing or the earlier incident has been asked to call 020 8721 4005 or Crimestoppers anonymously on 0800 555 111.