Dyfed-Powys Police continue to appeal for witnesses to a collision on Friday, in which four people lost their lives.
The incident involving two vehicles happened on the A470, Rhayader to Llangurig road shortly after 11:40am on Friday 27th March.
Both those travelling in the silver Vauxhall Agila died at the scene. They have been named as 77 year old Margaretta Jones and her grandson, 5 year old Ned Jones.
They were from Capel Bangor, Aberystwyth.
Two passengers of a second car, a red Seat Leon also died at the scene.
They were 86 year old Vida Alford and 58 year old Gillian Alford, both from Shropshire.
A 57 year old man, remains in hospital with serious injuries.
Specialist officers from Dyfed-Powys Police are supporting the families of all those involved and the coroner has been informed.
Anyone who saw either of these vehicles prior to the incident on Friday and has information which could assist with the ongoing investigation is asked to contact Dyfed-Powys Police on 101.