There is no obvious indication into what caused two skydiving instructors to be seriously injured as they landed near Queenstown on Saturday, according to preliminary investigations.
The Civil Aviation Authority which is leading the investigation into the accident near in Queenstown said a full investigation would now be launched to find out the cause.
Senior skydiving instructor Sasa Jojic and Sasa Ljaskevic, both from Siberia, were injured and are now recovering in Dunedin Hospital following the accident.
CAA spokesman Mike Richards said a preliminary review of available information failed to provide any indication of a single cause of the accident, so a thorough investigation would now be carried out.
"CAA was working with Police, WorkSafe and the operator NZONE to establish the circumstances around this accident which will help shape the direction of a safety investigation," Richards said.
Investigators will now gather and analyse the information and the aviation industry would be immediately alerted if a safety critical factor was identified to prevent the same accident happening again.
However the final findings into the accident may not be released for up to 12 months and was dependant on the complexity of the work involved.