A couple faces jail for keeping their six-year-old foster son restrained and undernourished in their garage, a Perth court has heard.
District Court Judge Frederick Sleight has delayed sentencing the 32-year-old man and his 34 year-old wife, who have pleaded guilty to deprivation of liberty and failing to protect a child, because he says the case is so complex.
The man has pleaded guilty to assault occasioning bodily harm but denies he hit the child.
The boy was found by police and child protection workers in a Perth suburb last year with fractures and bruises.
He was severely malnourished and had been kept in a cot with a plywood lid so he could not escape.
Prosecutor Linda Petrusa said he was a "a bag of bones" and was "dying in front of their eyes".
He was fed one or two meals a day and given some water while his guardians tried to control the eating disorder the wife had diagnosed him with over the Internet, Ms Petrusa said.
The boy had been given a screwdriver to bang on a saucepan when he needed to go to the toilet.
He had suffered heart failure shortly after being put into state care and had to be returned to hospital, the court heard.
It was extraordinary the boy's step-siblings, a 15-year-old, a 13-year-old, five-year-old twins and a 20-month-old, all had their own well-furnished bedrooms, Ms Petrusa said.
"The baby's bedroom had plush stuffed toys in abundance ... the household would appear to lack for nothing, yet this child was relegated to the storeroom," she said.
The child was given by his mother to the accused soon after he was born.
No legal adoption appears to have taken place, but the wife had signed custody papers giving her legal guardianship of the boy.
The child had been placed in the garage to try to control his eating compulsions, which included eating straight from margarine tubs and pancake mix containers, the court heard.
The wife had realised things were wrong and had made an appointment to seek help from authorities three days before police arrived to take the boy away, her lawyer said.