An investigation has been launched after a mayday call was received this morning, possibly from a plane flying near the Waimakariri Gorge in Canterbury.
Two helicopters were scrambled by Rescue Coordination Centre (RCCNZ) after the mercy message was received on an aviation channel, but no signs of a downed aircraftwere found.
An RCCNZ spokesman said a plane flying over the gorge, west of Christchurch, heard the call at 11.20am and notified air traffic controller Airways New Zealand, which told RCCNZ.
Garden City Helicopters pilot Neil Scott said two choppers had flown up the gorge, parts of which were covered in snow.
The aircraft which heard the call had also joined the search, which covered some 1000 hectares.
Airwaves New Zealand has inspected radar data of aircraft in the air at the time and haven't identified anybody, the spokesman said.
"Checks have been made to see if there's been any aircraft reported missing and that doesn't appear to be the case,'' he said.
"We're making an effort to speak to the pilot ourselves to clarify what the nature of that signal was, but at this stage the helicopters have been stood down pending any further updates.''
