Police investigating death of 5-year-old boy at home in Grafton

The police homicide squad is assisting investigations into the death of a five-year-old boy at a home in Grafton in the NSW Northern Rivers on Monday morning.

Warning: This story contains details of treatment of a child that may be distressing for some readers.

The ABC understands the boy's parents are being questioned over their treatment of the boy and his siblings in the lead-up to his death.

Emergency services were called by a family member around 6:40am on October 12 after reports that the child was unresponsive inside the home.

Officers began CPR on the child, and paramedics arrived a short time later; however, he was unable to be revived.

Police are investigating allegations that the boy and at least one other child had been duct-taped into sleeping bags to sleep at night.

Specialist police were called in to forensically examine the home, and police later said a post-mortem examination would be conducted to further establish the circumstances surrounding his death.

ABC News understands the family had been on the radar of the Department of Communities and Justice prior to the boy's death.

A Department of Communities and Justice spokesperson said it was working with NSW police to assist with their inquiries.

"The Department of Communities and Justice is aware of the tragic death of a young child in Grafton," the spokesperson said.

"Our heartfelt condolences go out to those who knew and loved this child."

The boy's parents have not been arrested, but are being questioned by police.

The matter has been referred to the coroner.