A couple from south-west Western Australia have been charged over the death of their six-month-old son.

Police are accusing the parents of neglect after the baby boy was rushed to hospital and later died.

Jahley Poata was just six months old and the youngest of eight children.

He was named after his own father, the man police say was responsible for his death along with his mother.

Police say it was June 1 when baby Jahley developed a medical condition, but it wasn't until four months later that the boy was rushed to Collie Hospital.

His condition was so critical he was transferred to Perth Children's Hospital.

The little boy was treated for more than a week but could not be saved. He died on Wednesday.

Police say his parents, Marea Hunia and Jahley Poata, neglected to provide him any medical treatment.

The couple, who are in their 30s, were arrested and charged by the child abuse squad.

The details of what happened or how the boy became so unwell remain unclear.

His parents today made no comment and showed no emotion as they fronted court for the first time, just two days after their child's death.

Tonight seven siblings are without their parents and their mum and dad are behind bars, awaiting another court appearance next week.