A 16-year-old boy has been arrested on suspicion of murder by police officers investigating the murder of Hazrat Wali in Twickenham.
He remains in custody at a south London police station following his arrest.
Police were called at 4:45pm on Tuesday, 12 October, to reports of a stabbing on a playing field in Craneford Way, Twickenham.
Officers attended along with London Ambulance Service and found an 18-year-old man with stab injuries.
He was taken to hospital, but was pronounced dead at 5:45pm.
He has since been named as Hazrat Wali, from Notting Hill.
His family continue to be supported by specially trained officers.
A post-mortem examination has been scheduled to take place at Kingston Mortuary tomorrow, Friday 15 October.
Information can also be provided to Crimestoppers, anonymously, by calling 0800 555 111.