Two fugitives on the run after the Canadian highway murders left behind key survival supplies when they fled a burning getaway car, it has been revealed.

More than a week into the desperate search for the teens accused of murdering Australian Lucas Fowler and two others, the manhunt has stalled after two of the strongest leads turned to dead ends.

But police are holding on to one hope: Even with their bush survival experience, Bryer Schmegelsky, 18, and Kam McLeod, 19, can not last long in the wilderness without food and outdoor clothing.

A volunteer firefighter who helped douse out the blaze engulfing one of the teens’ getaway cars has confirmed the pair had left behind canned food and camping equipment.

A RCMP officer searches in Manitoba, Canada. Photo: RCMP

“There were a few pots and pans in (the charred Toyota), a few canned foods, a crowbar,” Ty Blake told AAP.

Mr Blake, his fellow firefighters and police at the scene did not realise at the time it was the teens’ getaway car.

Chills went down their spines the next day when the RCMP announced it was the duo’s vehicle.

“When you sit and think about it, they may not have gone far and been sitting nearby in the bush,” Mr Blake said.

One of Canada’s leading survival experts warned there were plenty of dangers lurking in the swampy of sub-Antarctic boreal forest around Gillam, Manitoba, where it’s believed the teens could be hiding.

Dave Arama said the black bears, polar bears and wolves aren’t the biggest worry: it’s the insects.

There’s relentless blood-sucking deer flies, mosquitos, sand flies and other bugs.

“They eat you alive,” Mr Arama, owner of the Ontario-based WSC Survival School, said.

“They won’t stop biting until until your eyes close and you can’t see no more.

“Or, if you get enough bites you can go anaphylaxis and then end up in a serious life-threatening reaction.”

Water might be plentiful in northern Canada during summer but instead of keeping the teenagers alive it could also be highly hazardous.

“If they drink any water it is likely filled with parasites, giardia and they’d get sick as hell from that,” Mr Arama said.

In response to promising tip-offs from the public, the massive manhunt had been centred on two key areas in the Canadian wilderness: York Landing and Gillam.

The Royal Canadian Mounted Police appeared to be closing in on the pair after witnesses claimed they spotted the fugitives rummaging for food in bushland near York Landing.

Victims: Chynna Deese, Lucas Fowler and Leonard Dyck.

“A heavy police presence can be expected in the area,” the RCMP wrote on Twitter.

York Landing, which has fewer than 500 residents, is about 200 kilometres from Gillam – where the massive manhunt had previously been focused. It is accessible only by boat.

But despite dozens of police officers, sniffer dogs and drones combing the remote towns, there has been no trace of the pair and police have been “unable to substantiate the tip”.

They were now withdrawing their “heavy police presence” in York Landing.

Police also said they have completed their “door-to-door” questioning in Gillam after searching more than 500 homes in the wild town with a population of about 1260.

McLeod and Schmegelsky have been on the run since the bodies of Sydney backpacker Lucas Fowler, 23, from Sydney, and his American girlfriend Chynna Deese, 24, were found dead on the side of a highway 3000 kilometres away in Canada’s west on July 14.

The body of a third man, Leonard Dyck, a botanist aged 64 from Vancouver, was also found near the highway.

McLeod and Schmegelsky were first reported missing on July 19.

Officers have now completed their door to door canvasses in Fox Lake Cree Nation & the Town of Gillam. To date, over 500 homes have been visited by investigators. #rcmpmb

— RCMP Manitoba (@rcmpmb) July 30, 2019

The exhaustive search mission has been made even more disappointing by the revelation that First Nations police in Manitoba unknowingly stopped the fugitives during a routine check for alcohol but let them go, not yet aware the teenagers were the focus of a massive manhunt.

“We weren’t aware of their status, of them being wanted,” Band Councillor Nathan Neckoway told Candian news outlet, Global News. 

“Apparently after they came to our community, that’s when they sent out that wanted (status).”

Another local man has since come forward to relate his encounter with the wanted pair. Like Mr Neckoway, he wasn’t aware of their status until after their encounter

Tommy Ste-Croix revealed not only did he chat with Schmegelsky and McLeod, but he also helped them get their bogged Toyota RAV4 back on the road.

Kam McLeod, 19, and Bryer Schmegelsky, 18, remain on the run. Photo: RCMP

Mr Ste-Croix was visiting his brother in Cold Lake, Alberta, on July 21 when the family spotted a vehicle stuck in mud.

Mr Ste-Croix related the odd encounter on his Facebook page. It was a meeting that he said left him feeling “something wasn’t right”.

“Holy f***, my big heart could of (sic) got me killed,” he wrote. “One shot to the back and that would of been it.”

Mr Ste-Croix said he approached the car in an alley next to a football field and chatted casually with the fugitives. They told him their real names, joked with him and shook his hand.

“I pulled these guys out Sunday around 11 am, they still appear the same as in the pictures (from CCTV shared by police).

“Same shaggy beard, tall skinny fella was wearing a white shirt with camo army pants I believe … same hair cuts everything.

“They got stuck behind Cold Lake Hospital in a grey Rav-4. 2015-ish I’d have to say.

“Wish I’d of known, something wasn’t right with these guys. Even shook their hands after getting them unstuck. Blows my mind, guess I look like a mean motherf***er cause they were two and could of got my truck to take off with especially for being murder suspects.

Here's part of our interview with Sudbury-raised Tommy Ste-Croix, who unwittingly helped murder suspects Kam McLeod and Bryer Schmegelsky when they were stuck in Cold Lake, Alta. last week https://t.co/sdbbMPbEnm

— Waubgeshig Rice (@waub) July 31, 2019

Mr Ste-Croix told CBC News he joked with them that their parents would be mad if they knew the predicament they were in.

“Mom and dad’s going to be pissed,” he told them before one of the teens joked back.

“They looked at me and said, ‘No, mom and dad told me to go for a long joy ride’,” Mr Ste-Croix said.

He said the two teenagers shook his hand and did not make up fake names when he asked who they were. But he could sense something was amiss.

“You could tell they were nervous,” Mr Ste-Croix said.

The revelations have added to the mounting pressure on police, as the teens continue to elude a nationwide dragnet. But in an interview with US media on Tuesday, RCMP Corporal Chris Manseau said authorities “had to go where the evidence leads us”.

However, he also said police had not pulled officers away from searches in the Gillam area.

“We never want to put all our eggs in one basket,” Corporal Manseau said.

RCMP resources remain in the Gillam area and will continue to conduct searches in high probability areas for any signs of the suspects. The search of remote areas is being conducted both on foot and in the air. #rcmpmb pic.twitter.com/3QCPrQ4Tpw

— RCMP Manitoba (@rcmpmb) July 30, 2019