Yelling has reportedly been heard from a hut in the New South Wales Snowy Mountains where rescuers are searching for a Canadian bushwalker.
Prabhdeep Srawn began walking from Charlotte Pass Village to Mount Kosciusko more than a week ago and has not been seen since.
An air search for the 25-year-old is now focussed on a specific location within the Kosciuszko National Park where a voice has been heard.
The SouthCare rescue helicopter has also been tasked to the Opera House Hut area, but it is not yet confirmed if Mr Srawn has been found.
Hopes of finding the 25-year-old alive had been fading, with overnight temperatures in the mountains dropping as low as -2 degrees Celsius.
His family arrived in Australia on Tuesday.