Police were called to a man who had been stabbed in a home on Monson Road in New Cross around 7.30pm yesterday (August 2).
Officers arrived with medics from the London Ambulance Service and London Air Ambulance.
A 26-year-old man died at the scene.
His family are aware and is being supported by the police.
A 26-year-old man has been arrested on suspicion of murder and he remains in custody.
Detective Chief Inspector Lucie Card, who is leading the investigation, said: “Our thoughts are with the family and friends of the victim at this difficult time.
“I understand this incident will be concerning and we are carrying out a fast-paced and thorough investigation to establish the circumstances.
“I would encourage anyone who has not yet spoken to us.”
Police are asking anyone with information about the incident to call 101 quoting 6271/02AUG or message @MetCC on X.
You can also provide information anonymously to independent charity Crimestoppers on 0800 555 111 or online.
