TAIC is appealing for any witnesses of the crash, he said.
"We are keen to hear from people who saw the accident or who saw or heard the helicopter on this early morning flight between Milton and the Lammerlaw Range – particularly if you have photographed or captured the flight on video."
The commission has appointed an investigation team of three, who anticipate getting to the accident site tomorrow morning.
"The Investigation team's immediate evidence collection work is broad to support all avenues of inquiry. The initial focus is on gathering evidence that could disappear or change, such as the effect of weather on the wreckage."
To preserve the evidence, the commission has issued a protection order, prohibiting unauthorised access within a 200-metre radius of the main wreckage and unauthorised handling of any other wreckage or evidence relating to the accident.
"Over the coming days and weeks, TAIC's investigators will be recording the accident scene, recovering any remaining wreckage, securing electronic records – including photos, videos, and location data – and interviewing witnesses.
"We're interested in what people have to say, of course, particularly the helicopter's operator, and relevant professional and personal backgrounds of operational staff, what they knew, thought, experienced, and did."
TAIC opens an inquiry when it believes the circumstances of an accident or incident have, or are likely to have, significant implications for transport safety, or when the inquiry may allow findings or recommendations to improve safety.
The Civil Aviation Authority said it is working with police in Otago after the crash.
"Since being notified of the accident, our Investigation and response team has been in close contact with Police, who will be attending the scene today.
"Our thoughts are with the victim's family at this difficult time," the spokesperson said.
The chopper was believed to be flying from Milton to Alexandra and was reported overdue to Maritime NZ at 5.30am.
The Milton-based aircraft is believed to have flown up State Highway 8, towards Lawrence, over Glendhu Forest, before it crashed.
Another helicopter was sent to the scene at 7.30am.