Police were called at 8.32pm on Monday, 21 February to reports that a 58-year-old woman was found with injuries at a residential property on Church Street, N9.
Officers attended along with the London Ambulance Service. A woman was pronounced dead at the scene.
She has been formally identified as Susan Ioannou. Her family has been informed
Detectives from the Met’s Specialist Crime Command are investigating.
A 61-year-old man was arrested on Thursday, 24 February on suspicion of murder. He has been taken into custody.
A 33-year-old woman, who was arrested on suspicion of murder on Tuesday, 22 February, also remains in custody.
Anyone with information that could help the investigation is asked to call police on 101 or tweet @MetCC quoting reference CAD 6735/21Feb.
To remain anonymous contact the independent charity Crimestoppers on 0800 555 111.