Video Emerges From Couple's Final Days Before Brutal Murder

Haunting CCTV has emerged of Australian man Lucas Fowler hugging his girlfriend and filling up their Chevrolet van before the pair were murdered. 

The Royal Canadian Mounted Police (RCMP) released the footage from a petrol station in Ford Nelson, British Columbia, along with a sketch of a man they want to speak to in relation to the shooting murders of Fowler, 23, and Chynna Deese, 24.

In a press conference on Tuesday, police said the couple's deaths could be linked to the discovery of another body -- some 470km away -- and the disappearance of two Canadian teenagers.

"It is unusual to have two major investigations of this nature and we recognise the possibility these could be linked," RCMP Sergeant Janelle Shoihet said.

CCTV of Lucas Fowler and partner Chynna Dees at a petrol station in Fort Nelson on July 13. Photo: AAP via RCMP

Fowler, from Sydney, and Deese, from North Carolina, were stranded on a highway in British Columbia after their blue 1986 Chevrolet van broke down on the afternoon of July 14.

They were found shot dead on the roadside the following day.

READ MORE: Sketch Released In Hunt For Answers To Murdered Aussie And Girlfriend

On Tuesday, Shoihet showed a sketch of a person of interest -- a bearded man who was seen talking to Fowler before the couple were killed. He is described as "Caucasian with darker skin and dark hair".

"He's shorter than Lucas who stood six foot three (190 cm) and has a possible beard or glasses," Shoihet said.

A sketch of a man who the Royal Canadian Mounted Police say interacted with Lucas Fowler and Chynna Deese . Photo: AP via The Canadian Press

Canadian police also released CCTV of Fowler and Deese arriving and leaving a petrol station in Fort Nelson on July 13. The couple can be seen hugging, as Fowler fills up the van with petrol.

Fowler's father Stephen, a senior NSW police officer, told reporters the crime  has "torn two families apart".

“It is the worst ever love story," he said.

"We now have two young people who had everything ahead of them tragically murdered.”

READ MORE: Mystery Mounts Over Murdered Australian Lucas Fowler And Girlfriend 

Lucas Fowler and Chynna Deese. Photo: Facebook

Canadian police had initially fended off speculation the couple's murders were linked to the discovery of another man's body --  470km away from where Fowler and Deese were found dead -- near a burning red and grey Dodge pick-up truck.

The remains have not been identified, but the Dodge was driven by missing teenagers Kam McLeod, 19, and Bryer Schmegelsky, 18, from Port Alberni, British Columbia, who police on Sunday said have not been in contact with their family "for the last few days".

Explaining the change in a press conference on Tuesday, Corporal Manseau said police "just know more about both incidents".

Shoihet said investigators are not treating the teens as suspects but want them to contact authorities.

"We're hopeful they alive," she said.

Fowler's father Stephen said he remains hopeful for a positive outcome.

"As you know, I may have been an experienced police officer but today I'm standing here as the father of a murder victim," he said.

"We are just distraught.

"We are hopeful of a positive outcome and obviously we're appealing along with the RCMP for anyone to contact [police] who may have any information whatsoever, however little, please contact the police."

With AAP.