A toddler is now with Child, Youth & Family after being found outside a business premises in Kaikoura early on Sunday.
Police say members of the public found the child, aged 16 months, at about 2.45am on Sunday.
At 4.12am, police were contacted by a woman admitted leaving the child alone while she was "socialising". She was visiting Kaikoura from the North Island.
Police say the child was alone for approximately four hours, and had woken and left the house. It's possible the front door was open.
They say the child is in good health but will remain with Child, Youth & Family services while the matter is investigated.