"However, inquiries by police found that there had been no crash and there had been a training exercise carried out by the Northland Electricity rescue helicopter in the area at the time," she said.
Mr Turnbull said his staff had not notified emergency services of the exercise, and there was no need to.
Nest would not change its procedures around training exercises because there should not be any confusion.
"We do these exercises 20 times a year and no one is mistaken about them. There were people in the water at the time, they saw the helicopter and there was no way anyone could have misconstrued the situation. We informed our operations team but there's no obligation and it's unnecessary to tell others."
He said Nest received calls from St John, the Civil Aviation Authority and Coastguard and assured them it was an exercise.
Mr Turnbull said he spent half the time talking to civil defence agencies during the hour-long exercise.
Ms Kennett said Nest was a private company which did not need to inform police if it was carrying out its own training exercises.
"However, if they feel it may attract public attention then they are welcome to let us know. If there are major training exercises that involve emergency services then the public are informed," she said.
Senior Sergeant Rob Huys said it became obvious to police from the start that the matter was likely to be an exercise.
