The police dive squad has arrived in Tauranga following air traffic delays.
Flights were grounded at Tauranga Airport after reports of a drone flying around over Tauranga Harbour.
A police spokeswoman says a drone was seen flying near the Trinity Wharf Hotel and nearby apartments in Tauranga.
Police were notified just before 10am.
The police spokesperson says the control tower at Tauranga has to stop flight because of the drone.
The drone has not been found.
Police were called to the falls around 3pm and assisted two swimmers to shore.
A third person is yet to be found.