Family attending a Christmas get-together arrived to find police cars outside.
A relative told the Herald Imogen was the youngest of five siblings and lived at the house.
A friend of Imogen's father said the temporary pool had only recently been purchased by the family.
The man said he had been at the home on Christmas morning and the accident happened after he had left: "I went home and got a phone call".
Imogen had a lovely, vibrant personality, he said.
"She was a beautiful little girl, happy as - always smiling every day."
Meanwhile, a search is continuing today for a 16-year-old boy who was swept out to sea off 90 Mile Beach at Hukatere in the Far North where he was swimming with his family yesterday afternoon.
Hukatere Lodge owner Gabriele Pfaender rushed to the beach, fearing guests were involved. She spoke to the boy's distraught mother.
"She was just crying and crying and somebody had her in their arms. It's terrible, it makes me sick to think about it," she told the Herald on Sunday.
The current looked strong yesterday, Pfaender said.
"The sea is always different, one day it's like a lake and you can go in and other times it's a strong current and you wouldn't ... you've got to be careful in the water always."
Mr Li, who lived in Auckland, was with a group of friends setting crab pots when he and one other got into trouble.
His associate was able to make it back to the beach.
Police, Surf Lifesavers, Coastguard and the Rescue Helicopter were involved in the search. Mr Li's body was found 400 metres south of where he entered the water.
Police urged beach-goers to take care in the water with at least eight people getting into trouble in the waters off Uretiti beach over 24 hours yesterday. Most had been engaged in crabbing.
People were under-estimating the conditions and over-estimating their abilities, putting not only themselves but also those who go to their aid at risk, police said.
The easterly conditions that made the location popular for crabbing were the same conditions that made the beach dangerous.
Senior Sergeant Daniel Cleaver of Whangarei police said there were a number of popular beaches that were not suitable for people who were not strong swimmers, or were not able to swim.
"We advise all beachgoers to carefully consider the conditions of the surf before entering the water and not to go in if you don't feel confident."
Mr Cleaver said summer was a time to make great use of the beaches but warned the the ocean was a dangerous place.
"It is not worth risking your life for some time in the water. If you're not fully prepared, keep safe on the sand instead."
- additional reporting Herald on Sunday
