Emergency services have been called to Hunua Falls in South Auckland to rescue a man in the water.
Police were called to the falls at 11.19pm, a police spokesman said.
The spokesman said the man seemed to be floating down the river but was using his phone to stay in contact with St John Ambulance services.
However the phone had cut out just past midnight, which was hampering rescue attempts.
"He was talking to us but he's probably been in the water a while so he'll be getting a bit cold," the spokesman said.
