Australia's aviation authority has followed New Zealand and ordered the grounding of Robinson 44 helicopters with a particular rotor blade over safety concerns.
It was based on initial advice from investigators looking into the crash near Queenstown on Thursday, in which 18-year-old James Patterson-Gardner, and 42-year-old Stephen Combe, died.
They have suggested the crash could have been the result of a fault with the Dash 7 Main Rotor Blade.
The Civil Aviation Authority says the investigators have found similarities with a R44 incident in January.