Saddest garage sale: Toys and clothes belonging to four kids killed in car crash with mum are sold off by their aunt

The sister of the mum killed with her four children in a horror car crash in Queensland, has started the heartbreaking task of selling off their toys, bikes and possessions.

Charmaine McLeod, 35, was killed along with Aaleyn, 6, Matilda, 5, Wyatt, 4 and Zaidok, 2, when her car collided head-on with a truck on May 27.

The crash on the Bunya Highway near Kumbia in Queensland is being investigated by police as a spokesman revealed, 'there is a potential that there was an intention for someone to die.'

Now, Charmaine's grieving sister, Katie Harris, has listed their possessions on a Facebook group as she comes to terms with their deaths.

Photos of the items for sale show four children's bikes, a toy car, and a $100 dining table piled high with CDs.

On a local buy and sell group, Katie also listed mattresses. 

It's not clear why Charmaine veered on to the wrong side of the highway with her four kids in the car, or where the family were travelling to as they were three hours from their home. 

Investigators reportedly found a handwritten note 200m from the scene that led to homicide detectives being assigned to the case. 

There were no skid marks along the wrong side of the road where Ms McLeod's car hurtled towards the truck that crushed it and killed everyone inside. 

The crash was initially believed to be an accident as she overtook a truck, but the driver said she got around him safely.

Details of the family's funerals have yet to be announced but it is expected separate funerals will be held, in line with their father's wishes.