Lucas Robertson Fowler of Australia and Chynna Noelle Deese of North Carolina were found dead along the side of the Alaska Highway 20 kilometres south of the popular tourist destination on Monday, July 15.
Two NSW homicide detectives are also travelling to Canada to assist the investigation and support the family.
Canadian police said an old blue minivan was found at the scene and police are looking for anyone who saw the vehicle or can offer assistance.
Lucas Fowler in a post shared by his family on Facebook.
In a news release, BC RCMP stated they believe the crime occurred between Sunday and Monday.
He said his family was now travelling to Canada "to be with our boy" and to bring him home.More news: Netflix Debuts ‘The Witcher’ Trailer Starring Henry Cavill At Comic-Con
Police haven't confirmed reports the couple was shot to death.
"Maybe the van over heated or broke down", Chynna Deese's heartbroken brother, British Deese, told the Charlotte Observer newspaper.
A statement from the family of Sydney-area resident Lucas Fowler was posted on the website of the New South Wales Police Department.
"We are now travelling to Canada to be with our boy and to bring him home", says the post, which urges people to share it with all those who "crossed paths anywhere in the world with these handsome young people". "All our love and best wishes go to Chynna's family and friends".
"At this stage we can only move forward a minute at a time, and those minutes are moving so slowly".
"To know his handsome girlfriend, Chynna Deese, of Charlotte, North Carolina, also lost her life in this violent event is too cruel".More news: Heat warning in effect for Friday and Saturday
Deese's sister, Kennedy, wrote on Facebook: "It is with overwhelming sadness that I share my sister Chynna and her beloved boyfriend Lucas were recently found deceased".
They are also appealing for dash cam video from anyone who may have been travelling last weekend along the Alaska Highway, also known as Highway 97. They were bright and handsome souls.
They again pleaded to the public for information to help their investigation.
On her CouchSurfing page, Deese wrote that her "current mission" is to travel the world.
Anyone with information is asked to contact the Northern Rockies RCMP at 250-774-2700 or Crime Stoppers at 1-800-222-8477.
"Due to our privacy obligations we will not provide further comment", a DFAT statement said.More news: Eriksen trains alone on Spurs pre-season tour
Lucas Robertson Fowler of Australia was found dead along with his girlfriend Chynna Noelle Deese along the Alaska Highway in northern B.C. on Monday.