Chile has confirmed it is leading the investigation into how 50 people were injured on LATAM flight LA800 to Auckland on Monday.
People on board flight LA800 travelling from Sydney were thrown out of their seats and into the ceiling after the plane experienced a "sudden drop".
LATAM Airlines Group said the plane had a "technical problem during the flight which caused a strong movement believed to be a sudden drop".
In a statement on Tuesday, New Zealand's transport safety body - the Transport Accident Investigation Commission (TAIC) - said the Chilean accident investigation authority - the Dirección General de Aeronáutica Civil (DGAC) - was responsible for investigating what happened because it occurred in international airspace.
The agency has already opened an investigation.
However, it added the TAIC will be assisting in the investigation.
"TAIC is in the process of gathering evidence relevant to the inquiry, including seizing the cockpit voice and flight data recorders," the statement said.
Aviation expert Irene King told AM the lack of detail about what occurred was "very unusual".
"Given that they have said it's a technical issue, it could be anything from their systems having a glitch to an operator-induced glitch."
Hato Hone St John Ambulance treated injured patients, with Health New Zealand confirming five of them remain in hospital as of 7am this morning.
