Police were called by the London Ambulance Service (LAS) at around 13:35hrs on Saturday, 15 October to reports of a stabbing at an address in Buddings Circle, Wembley.
Officers, the LAS and London’s Air Ambulance attended and found an 18-year-old man with stab wounds. He was pronounced dead at the scene shortly before 14:00hrs. His next of kin have been informed.
Whilst officers believe they know who the deceased is, they await formal identification.
A post-mortem examination on Sunday, 16 October, gave cause of death as stab wounds.
Detectives from the Homicide and Major Crime Command are investigating, led by Detective Chief Inspector Andy Chalmers.
On Sunday, 15 October a 19-year-old man was arrested on suspicion of murder. He currently remains in custody at a north London police station.