The family of the Melbourne woman missing in the Canadian wilderness believe she may still be alive, and are calling for the Australian government to provide extra resources to find her.
Sophie Dowsley, 34, has been missing since taking a hiking trip around Statlu Lake on July 8 with her Canadian boyfriend Greg Tiffin, 44.
The lake is in the Rocky Mountains, about three hours drive from Vancouver.
Mr Tiffin's body was pulled from the lake by a dive team on July 18.
The lake's waterfall is notoriously hard to see from the hiking path, forcing sightseers to climb dangerously close to the edge of a sheer cliff to see it, 200 metres below.
Several tourists have slipped and fallen to their deaths trying to get a better view, locals say, and it is feared Mr Tiffin has became the latest of them.
Jamie Dowsley, Sophie's brother, told Fairfax Media there was no evidence to suggest she had also fallen in.
"We're 12 days into the search, and still there is no evidence that Sophie has fallen into the waterfall. We're hoping the fact Sophie wasn't found in the water, as authorities expected they would, this will give a renewed focus on the search.
"It was only two days ago when there were two consecutive days where there was no search on the ground, which is pretty hard to comprehend."
Because Sophie's body was not found in the water, searchers now suspect she did not fall in, and may have instead tried to find a way to access the water by land after Mr Tiffin fell. The weather in the region has been warm, Mr Dowsley said.
Helicopters and swift-water search teams have now been deployed, and an elite group of rescuers are preparing to abseil down the cliff-face to continue the search.
Mr Dowsley is calling for the Australian government to pressure its Canadian counterpart to provide extra resources to the search.
"There is no evidence to suggest she's fallen, which means she could still be alive," he said.
"Can you imagine what she's going through out there?
"She's injured, she's starving. She's seen her boyfriend fall to his death."
The police began their search on July 12 after the couple, who live in Vancouver, were reported missing.
"All search resources remain engaged as we continue to look for the missing woman," Royal Canadian Mounted Police spokesman Corporal Mike Rail told Fairfax Media.
"RCMP remain in close contact with the victim's and missing woman's families."
Kent Harrison Search and Rescue's Neil Brewer told CBC News British Columbia the waterfall had a history of fatalities.
"It's not an easy place to get into," he said.
"And I can't emphasise this enough: it has some extremely dangerous spots, with a very dramatic and very dangerous waterfall that exits from Statlu Lake."
Mr Brewer said he knows of three fatalities that have happened on this same area of rock.
