Paul and Sian Foley have held a third funeral for their son Lee after it took more than 18 months for his body parts to be returned to them.
Police add there is 'no evidence to date' to suggest carbon monoxide killed the two, believed to be a mother and her four-month-old baby.
Paul Marshallsea lost his job as a charity worker as he was on sick leave when he was seen dragging a shark away from children in Australia.
Fire officers have arrived at the house in the village of Troedyrhiw, where the bodies of an adult and a child were discovered yesterday.
The Merthyr Tydfil crew were called in by South Wales Police.
At the scene of double death in Troedyrhew, Merthyr. Mother and baby found dead in house on Church Street yesterday.
Woman named locally as Joanne Thomas. Baby said to be her three month old daughter. No word from police on identity of victims or cause.
Councillor Harvey Jones says he was shocked to hear news of the deaths of an adult and child in Troedyrhiw, Merthyr Tydfil.
– Councillor Harvey Jones, Merthyr Tydfil Council's cabinet member for schools
No doubt everyone in the community and in the wider part of the borough will be shocked by this. It's very sad news.
Police are treating the deaths of an adult and child in Merthyr Tydfil as unexplained.
The bodies, believed to be those of a woman and child, were found at a house in Church Street, Troedyrhiw, at around 4.20pm on Wednesday.
South Wales Police says next of kin have been informed and post mortem examinations are being arranged. An incident room has been set up at Cardiff Central Police Station.
– Detective Superintendent Paul Hurley
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. The information may seem insignificant but could be important to the investigation.
Detectives are investigating the circumstances leading up to the discovery of the bodies yesterday afternoon. Anyone with information is asked to call 101 or Crimestoppers anonymously on 0800 555111.
Borough councillor Gareth Lewis says news that an adult and child have been found dead in Merthyr Tydfil will have a 'big impact' on people locally.
Police were called to an address in Church Street in the village of Troedyrhiw at 4.20pm this afternoon.
– Councillor Gareth Lewis
It is a very close-knit community, the people are very nice and will help the police as much as possible with their inquiry.
The information started to spread online, and it will have a big impact on this community and its people.
Troedyrhiw is part of an old coal-mining area, which Mr Lewis described as a 'typical, traditional Valleys community'.
An adult and a child have been found dead at a property in the Troedyrhiw area of Merthyr Tydfil, South Wales Police have confirmed.
Police were called to the Church Street address at 4.20pm this afternoon.
Officers are currently at the scene, which has been cordoned off, while house-to-house enquiries are being carried out in the area.
The increasing problem of metal theft is being highlighted by all four of our police forces.
They have held a summit today to discuss the best way of tackling the issue.
Thieves have now damaged what is considered to be one of Wales' ancient monuments - the former Cyfarthfa Ironworks site.
One of Wales' icon industrial heritage sites has been hit by a spate of robberies by thieves looking for metal.
Merthyr Council says iron has been taken from the Blast Furnaces on the remains of Cyfarthfa Works.
Individuals were seen destroying stone and brick work to steal metal lintels and sell for scrap.
The Blast Furnaces at Cyfarthfa are the best preserved examples from the industrial revolution in the world and are protected as ancient monuments.
Today representatives from Wales' police forces will meet at a summit in Cardiff to discuss how best to tackle metal theft.
The crime is estimated to cost the UK some £220M a year, and although the level of theft has dropped by 27% in Wales, tackling the crime still remains a priority.
South Wales Police Deputy Chief Constable Matt Jukes says "Metal theft remains a problem, and we want to ensure that the people who are in the jobs tackling this crime head on know what the legislative changes are and know how to take full advantage of them."