Sydney man Lucas Fowler and his American girlfriend were shot dead on a remote Canadian highway, New South Wales police have confirmed.

Key points: Lucas Fowler and Chynna Deese died in a double shooting homicide, NSW Police have confirmed

Lucas Fowler and Chynna Deese died in a double shooting homicide, NSW Police have confirmed Canadian authorities played down rumours of a serial killer or any connection to other recent murders

Canadian authorities played down rumours of a serial killer or any connection to other recent murders Mr Fowler is the son of senior NSW policeman Stephen Fowler

Mr Fowler, 23, the son of senior New South Wales policeman Stephen Fowler, and Chynna Deese, 24, were found dead on Monday on the side of the Alaska Highway in British Columbia.

Canadian authorities confirmed their deaths as a double homicide, but had not revealed how the pair died.

NSW Assistant Commissioner Mark Jones said they have been told the young couple was shot in "what can only be described as horrific circumstances".

"The RCMP (Royal Canadian Mounted Police) are running this investigation, but our understanding is that they were with a vehicle in the northern part of British Columbia, and it appears they may have been shot in that location," he said.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 1 minute 14 seconds 1 m 14 s NSW Assistant Police Commissioner Mark Jones said the young couple were shot dead.

Assistant Commissioner Jones said the incident was particularly sad for NSW Police because Lucas's father, Stephen, is a serving police officer.

"Our heartfelt condolences go out to both families, but certainly being you know a very competent experienced and fantastic police officer, it's just made all the more sad for Stephen and his family," he said.



Earlier, Canadian police sergeant Janelle Shoihet said there was no evidence that a serial killer was responsible.

"At this point there's nothing to indicate that these rumours are true," she said.

Sergeant Shoihet was responding to a journalist's question about international media reports of a possible serial killer at large.

"We want to assure you that this is a unique situation in northern British Columbia, there's no indication there's been a spike in any crimes," she said.

A blue minivan with number plates registered to Alberta was found at the scene. ( Supplied )

The two were killed sometime between July 14 and 15, police confirmed, and were found 20 kilometres south of Liard Hot Springs.

Police were alerted to a blue minivan with Alberta registration plates at the scene, and authorities wanted to speak with anyone travelling in the area who may have had dashcam footage.

"They received a call in relation to this blue van and the two individuals — it's my understanding that the investigators are still at the site … and we are committed to providing any and all resources that are required," Sergeant Shoihet said.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 28 seconds 28 s Canadian police are seeking public help with their investigation into the murders.

In a statement released on Friday night, the Fowler family said it was travelling to Canada to bring Lucas home.

"We have lost our dear Lucas Fowler, son, brother, grandson and friend, in the most terrible of circumstances. To lose someone so young and vibrant, who was travelling the world and just enjoying life to the full, is devastating.

"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.

"We are all now travelling to Canada to be with our boy and to bring him home.

"Our deepest thanks for all your love and care. At this stage we can only move forward a minute at a time, and those minutes are moving so slowly.

"Please share this with all those who may have crossed paths anywhere in the world with these beautiful young people."

Lucas Fowler was "travelling the world and just enjoying life", a family statement said. ( Supplied: NSW Police )

In a statement on Facebook, Ms Deese's sister, Kennedy Deese, paid tribute to the pair.

"It is with overwhelming sadness that I share my sister Chynna and her beloved boyfriend Lucas were recently found deceased, homicide victims along a remote stretch of Canada while on a road trip," she said.

"They were bright and beautiful souls. We are all still in shock and heartbroken."

"Instead of watching you enjoy your thriving life, I can only carry your legacy in mine, and encourage others to do the same. I will miss you every moment. And love you forever, best friend."

The couple's bodies were found on a highway south of Liard Hot Springs. ( Supplied )

A Canadian family has confirmed Mr Fowler left their ranch the day before it is believed he was killed, and where he died is only a few hours away.

Erika Weder said Mr Fowler was an easy-going ranch-hand who loved to travel.

"It's about four and a half, five hours from our place here, it's just unbelievable, we're shocked — I don't know what to say," she said.

Lucas Fowler and Chynna Deese had been travelling the world. ( Supplied: NSW Police )

The Department of Foreign Affairs and Trade said it was providing assistance to Mr Fowler's family.

Homicide squad detectives from New South Wales have flown to Canada to help liaise with the family and Canadian authorities.

"The man is the son of a serving officer and as such we are providing support to him and his family," police said in a statement.

"Our thoughts are with them at this difficult time.

"The investigation into this incident is being led by the Canadian authorities and as such, they will be the appropriate source of information as it comes to hand."