Police are asking the public for more information after a couple was found dead on a northern B.C. highway earlier this week.

The RCMP says the adults were found on the Alaska Highway about 20 kilometres south of Liard Hot Springs Monday morning.

They were publicly identified Friday as American Chynna Noelle Deese and Australian Lucas Fowler.

Their deaths were initially considered suspicious, but Mounties have since said they're treating the case as a double homicide.

"It's not yet clear if Lucas or Chynna were targeted or if this was a crime of opportunity," Sgt. Janelle Shoihet told a press conference Friday.

Police wouldn't confirm how the couple died or how the two were discovered.

“This is tragic, other than saying our hearts go out to friends and families…it’s going to touch everybody and we’re absolutely committed to advancing the investigation to the best of our abilities,” Shoihet said.

Mounties say Fowler is believed to have been living in B.C., and Deese was visiting him.

In a statement released through the New South Wales Police Force in Australia, Fowler's relatives said his family is travelling to Canada "to be with our boy and bring him home."

Local media have reported Fowler was the son of a chief inspector with the NSW police.

His family described Fowler as a son, brother, grandson and friend who was lost in a terrible circumstance.

"To lose someone so young and vibrant, who was travelling the world and just enjoying life to the full, is devastating," the statement said.

"To know his beautiful girlfriend, Chynna Deese of Charlotte, North Carolina also lost her life in this violent event is too cruel. All our love and best wishes go to Chynna's family and friends."

The Fowler family thanked those who have reached out to express their sympathy, and asked that their statement be shared with anyone who'd crossed paths with the couple.

"At this stage we can only move forward a minute at a time, and those minutes are moving slowly."

Deese's mother Sheila says the pair were in love.

"They had plans for the future. They were meant to be. She loved him so much," she told American media.

Deese's brother said the pair were found brutally murdered, and most of their belongings left behind.

He identified the van in the photo as belonging to Fowler, who he says bought it from a cattle ranch he was working on.

Officers are looking to speak to anyone that used that stretch of highway between Sunday at 4 p.m. and Monday at 8 a.m.

They're also looking for information on a blue minivan with Alberta plates. In a statement issued Wednesday, the RCMP said the vehicle was found at the scene, and investigators want to speak to anyone who saw it or possibly assisted the van's occupants.

Shoihet says the RCMP is working with the FBI to investigate the case.

"We recognize this news is very troubling to the entire community, and absolutely appreciate there are concerns for peoples' safety," she told reporters.

A woman who told CTV News she'd seen the van said it appeared to have broken down on the side of the northbound lanes.

"The hood was up and there was a young couple sitting in lawn chairs in the ditch. The girl got up and waved at me," Carrie Haruluk said.

She said she couldn't help - her vehicle was full and there were vehicles coming in both directions - so she kept driving.

"The next morning, we all heard the sirens," Haruluk said.

"It's disturbing because it's somebody's daughter, it's somebody's son. And they're not very old."

One woman who did stop to see if the pair was okay said they seemed happy and relaxed.

Sandra Broughton says they pulled over to talk to the pair, with the two telling Broughton one of the van's engine cylinders had flooded and they were having a picnic and waiting.

"We just asked if they were okay if they had enough food and water and they said they were okay so we just went on our way," she told CTV News.

Broughton said the pair seemed to be happy and thought their car problems would be fixed.

"It was a shock because we just seen them and they were okay and then to hear such a tragic that happened," she said.

The region's mayor says he's offering his sympathies to the victims' families, but didn't have any more details other than what the RCMP have released.

In addition to those who'd seen the van, anyone with dash cam video of the area also asked to come forward. Tips can be left with the Northern Rockies RCMP at 250-774-2700 or anonymously through Crime Stoppers.

With files from CTV News Vancouver's Sheila Scott and Allison Hurst