FARMINGDALE, N.Y. – A routine child welfare investigation led to the discovery Saturday of a toddler's corpse buried in the backyard of a Long Island home.

State police unearthed the remains in the dead of night at a tidy house in Farmingdale after being told by the boy's mother that he died two years ago. The circumstances of his death remained unclear Saturday.

The boy, Justin Kowalczik, was about 17 months old when he died in the summer of 2010, police said. Authorities said the family never reported the child's death.