South Wales Police say they now believe the two bodies found in at an address in Merthyr Tydfil were a mother and young child.
Detectives are treating the deaths as unexplained and the bodies have not yet been formally identified, police added.
Troedyrhiw is a close-knit community in Merthyr Tydfil and local people are obviously shocked.
We have a team of officers at the scene and in the community looking for information that may assist our enquiries.
We would like to hear from anyone who has seen or heard anything suspicious or unusual in Church Street in recent weeks.
More top news
Jay Oxley was diagnosed with a rare form of cancer and had to be put into a coma.
UKIP leader Paul Nuttall is set to contest the Stoke Central by-election later this year according to ITV Central's Political Correspondent
Jeremy Corbyn has accused Theresa May of producing a "bargain-basement Brexit" plan and "demeaning" the UK's European standing.