Canadian authorities are asking the public to "remain vigilant" after the highway murder of Australian tourist Lucas Fowler and his US girlfriend, the discovery of another body and the disappearance of two teenagers.
The incidents took place in remote northern British Columbia over the last week.
Royal Canadian Mounted Police have repeatedly fended off speculation a serial killer was on the loose and have not publicly linked the incidents, but on Sunday acknowledged "there are growing community concerns about the ongoing homicide investigations in northern BC".
"At this time, investigators are sharing information and police would like to ensure awareness around both investigations," RCMP spokesperson Dawn Roberts said.
"The RCMP would ask the public to continue to take any general safety precautions and remain vigilant at this time.
"We also remind travellers to share your plans with family and friends, establish check-in times and notify someone if your plans change."
Mr Fowler, 23, the son of a senior NSW police officer, and his North Carolina girlfriend, Chynna Deese, 24, were shot dead after their blue 1986 Chevrolet van broke down on the side of the Alaska Highway 20km south of Liard Hot Springs a week ago.
Suspicions were raised when another body was found on Friday near a burning red and grey Dodge pick-up truck that had a distinctive sleeping camper attached.
The body has not been identified but the Dodge was driven by 19-year-old Kam McLeod and 18-year-old Bryer Schmegelsky from Port Alberni, British Columbia.
The RMCP said Mr McLeod and Mr Schmegelsky "have not been in contact with their family for the last few days".
The Dodge was found near Dease Lake, approximately 470km away from where Mr Fowler and Ms Deese were found dead.
Police confirmed the body discovered near Dease Lake was not Mr McLeod or Mr Schmegelsky.
The teenagers were travelling through BC to visit Whitehorse in the Yukon Territory to look for work and the RCMP said it "is not clear why they returned to BC and what their travel plans may be".
"Kam and Bryer have periodically connected with family and friends over the past week and it is possible that they are now in an area without cell coverage," Ms Roberts said.
"However, we have found their vehicle and have not been able to locate either of them at this time.
"We are asking for Kam or Bryer to connect with police right away and let us know you are okay.
"Or we ask that anyone who may have spoken to or seen them over the last few days to call police so we can get a better understanding as to where they might be or their plans."
They said it was unclear how the dead male near the Dodge might be connected with the vehicle fire or the two missing teens.
Mr Fowler is the son of NSW Police Chief Inspector Stephen Fowler, who has flown to Canada with other family members and two NSW homicide detectives.
Mr Fowler and Ms Deese met backpacking in Croatia two years ago, fell in love and embarked on a Canadian road trip in the old Chevrolet.
Passing motorists saw the stranded couple alongside their broken-down vehicle.
Canadian couple Curtis and Sandra Broughton stopped to offer help about 3.20pm on Sunday.
Mr Broughton, a mechanic, told AAP he spoke to Mr Fowler but the young Australian seemed to know how to fix the van so the Broughtons left.
Perhaps the biggest clue came from a road worker, Alandra Hull, who told the Nine Network she saw Mr Fowler and Ms Deese on the highway the night before they were found dead talking to a man who "kind of looked frustrated or something".
That man was standing in the highway staring at Mr Fowler and Ms Deese.
Ms Hull is working with an RCMP artist to provide a sketch of the man.
