The parents are understood locally to be called Gary and Tania Clarence.
A woman was taken to hospital for treatment for minor injuries and later discharged. She was then arrested on suspicion of murder and taken into custody at a south London police station. A neighbour, who did not wish to be identified, said the family were originally from South Africa and had moved into the large semi-detached house with their four children a year ago.
Officers are not looking for anyone else in connection with the incident and are currently not giving any details on the possible cause of the deaths. Post-mortem examinations will be arranged in due course.
BBC London 94.9’s Jason Rosam said neighbours told him the family had recently moved into the house and there is a suggestion some of the children had disabilities. One said the young children were suffering from genetic disorders – believed to be life-limiting – but the eldest child, thought to be around seven or eight years old, was in good health.
“They are a very, very lovely couple. I saw them all the time about with their children,” the BBC quoted a neighbour.