Technical examinations at the scene in Moygara, Co Sligo, in which a father and his two children died, continued today.
Gardaí and Sligo's Chief Fire Officer examined the ventilation in the house.
It is believed carbon monoxide caused the deaths of Trevor Wallwork and his children, Kimberley and Harry.
The open fireplace in the sitting room of the local authority house is also a focus of attention.
Post mortems on the three bodies were completed at Sligo General Hospital last night by the Deputy State Pathologist Dr Michael Curtis but further toxicology tests will have to be conducted.
It is expected that it will take a number of weeks before the results of those will be known.
It is unclear at this stage when or where the funerals of Mr Wallwork and his children will take place.