St John said a child was treated and taken to Starship Hospital in a serious condition.
A police spokeswoman confirmed the child involved was a 4-year-old boy.
Acting inspector Jason Homan said the boy was found floating in an unfenced pool by his father, who then carried out CPR on the youngster.
"Parents have come out to find him floating in the pool unresponsive,'' Homan told Fairfax.
"The father has done CPR. When emergency services arrived, he was in a critical condition having CPR being conducted.''
An Orewa resident, who asked not to be named, said she arrived at the beach after the incident but had seen emergency services in the area.
"There was fire engine parked on [the beach] side and the helicopter landed across the road in the field," she said.
Police said it was another timely reminder for parents and adults to keep an eye on their children in and around the water this Summer.
Today's near drowning comes almost a week after a 4-year-old boy was found unresponsive in a pool in the east Auckland suburb of Beachlands.
The boy and his family were at a property on Constellation Ave on Christmas Day when tragedy struck.
