The offer was posted Monday on a Facebook page devoted to finding Prabhdeep Srawn of Brampton, Ont.
The 25-year-old has been missing since May 13 when he went for a bushwalk at Kosciuszko National Park in New South Wales.
The family had originally offered a reward of $15,000.
The official search for the Canadian military reservist wound up over the weekend.
But Srawn's family and supporters still believe he'll be found alive because he had extensive survivor training and hiking experience.
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