A 16-year-old boy has become the third person to be arrested in connection with the death of a man who was killed at an address in Roehampton.
The victim, believed to be Martin Thomas, was found with serious injuries following an alleged break-in at a property on Tuesday evening.
Two boys, aged 15 and 17, have already been arrested on suspicion of murder.
Officers said they are continuing to appeal for information so they could identify three individuals seen in the area prior to the incident.
More top news
London mayor Sadiq Khan is "extremely worried" about knife crime as Met Police revealed there was an increase in stabbings in the capital.
Camden police have responded to reports of an unexploded World War Two bomb in Hampstead high Street.
AFC Wimbledon face Plymouth in the League Two play-off final at Wembley, with a place in League One at stake.