A 4-year-old boy found severely injured in his Flaxmere home in January has been discharged from Starship Hospital.
The boy suffered extensive injuries, including brain damage, while under the care of his immediate family.
More than four months later, no one had been charged with his assault.
Detective Inspector Mike Foster said the boy was recovering at a rehabilitation facility in Auckland, under the care of a relative.
"He is doing well, but he will remain a sick little boy."
Police were still waiting on expert medical reports before deciding whether charges could be laid.
The boy's immediate family initially declined to cooperate with the police investigation into the incident.