Mandeep Srawn, sister of 25-year-old Prabhdeep Srawn, spoke to CBC News via Skype on Saturday morning, after rescue officials briefed her family on the latest developments in the search, as it continued for a 12th day.
She said officials talked about hearing distant voices Wednesday within Kosciuszko National Park, in New South Wales, and of finding a water bottle that could be his.
"They've gone over the areas on the map of what they have searched and where they'll be searching tomorrow and how they covered this area.
"They went where the voices were heard and they showed us where the bottle was found," she said, adding the voices were heard below the snow line.
Prabhdeep Srawn was a reservist from 2005 to 2001, belonging to the 31 Service Battalion's Hamilton Company and had military training in extreme conditions.
"He's experienced," he sister said. "As all of his fellow soldiers will say, he's probably one of the best and he's excelled at the hardest courses they have there."
Her brother hasn't been heard from since parking his rental car on May 13 in the village of Charlotte Pass in Kosciuszko National Park. The car was found that same day and police say they believe he got lost in the freezing conditions.
"This is a safe and easy trail to walk, but he had chosen to walk out, on the day he went missing, when a blizzard hit. It threw him off course, and possibly blinded or whited-out the track completely and he couldn't find his way back, " Mandeep Srawn said.
The vast national park covers nearly 7,000 square kilometres. Mandeep said rescue officials have narrowed down the search area to 100 square kilometres where they think he may be found.
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Prabhdeep Srawn, who was born and raised in Hamilton, has been studying law at Bond University in Australia for the past two years. His family moved to Brampton, Ont., in 2012.
"I'm still holding onto hope and I will until he is found," his sister said.
"I know he's out there. He's the strongest and smartest person I know, and I know everybody back home feels the same way, that if it was anyone else we'd be a lot more worried than we are," she says.
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