A three-year-old boy and a girl aged 11 along with two adults were found dead in the property in Staines Road, Bedfont yesterday afternoon.
Whilst formal identification is yet to take place, they are believed to be Michal and Monika Wlodarczyk, 39 and 35-years-old respectively, 11-year-old Maja Wlodarczyk and 3-year-old Dawid Wlodarczyk.
All four are thought to be related.
Officers are still trying to locate relatives and they continue to appeal for information.