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.
– Detective Superintendent Paul Hurley, South Wales Police
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.