Rescuers are deciding whether to make a risky trip on to a ski feld in freezing conditions tonight after a skier was seen lying under power lines in Arthur's Pass National Park.
Police say it is unknown at this stage whether the man is still alive.
Southern communications team leader Mike Murphy said the man was speed flying at Temple Basin ski field this afternoon.
Speed flying is skiing with the aid of a fabric wing, which adds speed and lift.
The man had set off for a run down the slopes but emergency services were called when he failed to arrive at the bottom within minutes.