Toddler leads police to NSW drug house

A toddler wandering alone in the streets of Port Macquarie at 4am has led NSW police to cannabis plants growing in his parents' house.

The three-year-old boy was wearing only a nappy when police found him early on Saturday.

After tracking down his address, they went to his home to find no parents, two siblings aged 16 and 18, and a large hydroponic cannabis greenhouse.

Seventeen cannabis plants, an unregistered firearm and a crossbow were seized from the house, local police told AAP on Monday.

Officers said the house was in a putrid state with no food and only a carton of milk and two slices of watermelon in the fridge.

The 39-year-old mother was later charged with taking action resulting in health/physical damage and taking part in cultivating a prohibited drug.

She will face Port Macquarie local court in April.

Community services removed the toddler from the home, while orders have been made to remove another sibling aged eight who was believed to be with the father.