Senior Sergeant Allan Grindell, of Wanaka, said the man passed away after "getting into difficulty in the water" and the cause of death was not yet known.
A St John spokesman said ambulances were called to the scene, but no-one was transported to hospital.
A police spokeswoman earlier said they arrived at the scene about 3.10pm.
Witnesses described seeing the man being given CPR at the scene after he earlier collapsed in the water.
There was little detail about the incident, but it involved a "person in the water".
Police said in a statement just after 4pm a man was still being treated at the scene.
Meanwhile, a Wanaka paraglider received moderate injuries after crashing on Treble Cone today.
Police said a statement emergency services were contacted about the incident at 1.20pm.
The Alpine Cliff Rescue team assisted the 44-year-old local man, who was then taken to Lakes District Hospital by helicopter.
An organiser of the NZ Paragliding Open, which is being held in the area, said he was not a competitor in the event.
He was understood to be an Australian man who lives in Wanaka.