Family of missing Melbourne hiker voice desperation after tragic find of her boyfriend's body.

The family of a Melbourne hiker missing in the Canadian wilderness are living their “worst nightmare” but say they are clinging to hope she will be found alive despite the discovery of her boyfriend’s body in a lake.

Sophie Dowsley, 34, went hiking on July 8 with 44-year-old Canadian Gregory Tiffin in the Statlu Lake region, three hours east of Vancouver.

Four days later, concerned family and friends alerted authorities. Then on Thursday, Canadian search and rescue teams on Thursday found Tiffin’s body in Statlu Lake.

Today Dowsley’s family members say they are holding onto “every bit of hope” that she didn’t follow her partner over the waterfall into the lake.

“It’s hard to comprehend that she has fallen down there, given that there’s no evidence,” her brother Jamie Dowsley told the Nine Network after returning to Melbourne from Vancouver.

“They found Greg’s backpack further downstream on the same day that they found the car, which is a Wednesday. But the only evidence of Sophie is a pair of sunglasses carefully placed on a rock at the top.”

The discovery of Tiffin’s body will hopefully encourage search efforts to be stepped up and there could be a greater role for the Australian government, Jamie Dowsley said.

“Hopefully it can increase the urgency of the search. We are 12 days in and we are desperate,” he told 3AW radio. “We feel we need the help of our government. We don’t know what that help looks like.”

He said the Department of Foreign Affairs and Trade “basically told us there is nothing they can do.”

What it’s like when a loved one goes missing. Post continues below.

Statlu Lake is renowned for its beauty but the region is remote and its trail challenging for experienced hikers.

Royal Canadian Mounted Police spokesman Corporal Mike Rail called the territory “gorgeous, but unforgiving.”

“We’ll keep searching until either we find her or we have searched everything we can possibly search,” he told AAP. “You never give up hope.”

Dowsley had been living in Canada for about three years and her family flew there as soon as they realised she was missing.

“It’s the worst possible nightmare that you could imagine,” Dowsley’s father, Peter, told Canada’s CTV News. “I couldn’t dream of anything worse.”