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
163,000 French and 143,000 German soldiers were killed in the 10-month battle in 1916.
As many as 700 migrants have been died after three consecutive days of shipwrecks off the coast of Libya, the UN Refugee Agency has said.
The fire broke out on Sunday morning at the home for 35 residents in Litochki, a village 25 miles north of Kiev.