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
Aidan McAteer, 23, pleaded guilty via video link as Violet-Grace's mother wept in the public gallery.
The wife of a man who filmed himself killing their baby in Facebook videos, said she is not angry at the site or those who shared the posts.
Moyes told the BBC reporter she "might get a slap" following a post-match interview when Sunderland drew 0-0 with Burnley.