Police have named the mother and daughter murdered at a home in Hackney as one-year-old Real-Jahzarah McKoy and 45-year-old Valerie Forde.
A murder investigation was launched on Monday after Met Police officers and the London Ambulance Service found the two victims as well as a 53-year-old man suffering injuries at the east London home.
They had been called at 9:11am to reports of three people injured at an address in Oswald's Mead.
The 23-month-old baby girl and her mother were both pronounced dead at the scene while the man, who has been arrested on suspicion of murder, was taken to an east London hospital with non-life threatening injuries.
Neighbours had gathered near the terraced house as police cordoned off the area to continue their investigations.
A post-mortem examination of Forde, a youth support worker, will take place at Poplar Mortuary on Thursday, 3 April, while Real-Jahzarah's will be on Wednesday, 2 April, at Great Ormond Street Hospital.
The Directorate of Professional Standards has referred prior contact with the victim to the Independent Police Complaints Commission.
Anyone with information can call Crimestoppers on 0800 555 111