A young child was taken to hospital earlier this month after being found at a Bay of Plenty motel where P was allegedly being smoked.
Senior Sergeant Mark Pakes said police went to the motel after receiving information from a member of the public.
Police made three arrests and took a 19-month-old to the hospital.
Police later referred the child to welfare services.
Police charged a 24-year-old woman with allowing premises to be used to use methamphetamine, Mr Pakes said.