Local police are investigating the possibility of carbon monoxide poisoning from a makeshift fire used to heat the cabin on Browns Road in Kurrajong. Carbon monoxide is a colourless, odourless gas produced when wood, coal and other fuels burn. It can build to dangerous levels when burning fuels are brought inside, to poorly ventilated areas.
The cabin appears to have been a converted shipping container, and Australian media are reporting the deadly gas may have come from a pot of hot coals the couple brought inside.
"It appears they had some sort of makeshift heater inside the cabin and there wasn't any ventilation, and as a result of that they may have asphyxiated," New South Wales police Detective Inspector Suzanne Rode-Sanders said at a news conference.
"At this stage it appears to be just a horrible accident."
The cause of death will be confirmed by the coroner after a post-mortem.
The Sydney Daily Telegraph called Kehler, 32, and Curic, 31, "creative souls with a full life ahead of them."
A family member discovered their bodies at about 7:40 a.m. local time Monday, according to a statement by the New South Wales police force.
"As you can appreciate, it was a horrific incident especially for one of the relatives to walk into, so our thoughts go out to the family," says Rode-Sanders.
"They're quite devastated ... very emotional and very upset."
'There's so much of him in his own songs'
Friends of Kehler, who lived in Vancouver before moving to Australia last year, confirmed their identities to CBC News.
Kehler grew up as a "farm kid" in a small town in southern Manitoba, according to his former Vancouver roommate Zach Gray.
"He was such an easy guy to have around, because he's such a seize-the-day kind of person," said Gray.
"He had a really loud laugh and he used it all the time, at himself more than anyone. He also had a kind of depth and loyalty to him."
Gray described Curic as funny and brilliant. "She just charmed us all immediately," he said.
"When they first moved to Sydney, they said it was just for a few months, but we all kind of knew that that was just a pretense, and what was really happening was that they had found each other and they were riding off into the sunset together," he said.
Gray said he has been dealing with his shock over the couple's death by listening to Kehler's country music.
"Old-style, Johnny Cash-style country music about love and death and loneliness and heartbreak," he said. "It's music you can sort of lean against when things are hard, and that's why we've been listening to his music so much in the last couple of days.
"It's kind of equally comforting and heartbreaking that there's so much of him in his own songs."