He said the dog owners were a young couple on holiday from Taupo.
"They were on a walk with their dog when she ran under a little old scout hall. The dog would have been one or two years old, a little foxy.
"The concrete was probably about 10 inches (25.4cm) thick so we couldn't cut through it.
"We found an area further away where the concrete was thinner and we managed to get through.
"An hour or so later and the dog and owners were reunited - although I'd imagine she probably spent the rest of the night in the dog box.
"It was very unusual, but we had a happy ending."
Mr Christini said they had been called to a cat up a tree before and some years ago they had a seagull caught in a line that they had to untangle, but nothing like this before.
"She was on a mission, you wouldn't think a dog would go that far down a rabbit hole."