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
Ryan Giggs has ended his long association with Manchester United, the Premier League club have confirmed.
Conservative leadership hopeful admits he "did everything possible" to avoid joining the race but claims he is the best person for the job.
Tiny New Zealand town with too many vacant jobs and affordable homes received 10,000 messages globally after putting out a call.