A father and his 13-year-old daughter have been arrested over the murder of her former boyfriend.
Sumon Miah died from head injuries
Sumon Miah, 21, died in hospital on 17 October, nine days after he suffered serious head injuries at the family's house in Walthamstow, east London.
The girl's brother, 13, and mother, 41, have been arrested on suspicion of perverting the course of justice.
Scotland Yard has referred concerns over the handling of the case by its officers to a police watchdog.
The 13-year-old girl has also been arrested on suspicion of perverting the course of justice.
Police were called to the family's house at 1530 BST on 8 October over reports of a disturbance and discovered Mr Miah.
The Independent Police Complaints Commission (IPCC) is investigating the force's handling of the case with regard to phone calls received from the family's address.