Britain's Foreign Office says four Britons were among six people killed when a sightseeing seaplane crashed in a remote area near Tadoussac, Que.

"Sadly, four British nationals were on board the plane that crashed in Les Bergeronnes, Canada on Sunday," a British Foreign Office spokesperson said. "Our deepest sympathies are with their friends and family at this difficult time. Our consular officers are ready to provide assistance and we will remain in contact with Canadian authorities regarding this tragic incident."

The ministry did not give the names of the victims of Sunday's crash in the rugged and heavily wooded North Shore region.

On Monday, Quebec provincial police confirmed all six people aboard the de Havilland Beaver float plane had died, including pilot Romain Desrosiers and French tourist Emilie Delaitre, 28. 

Emilie Delaitre

Emilie Delaitre from Côte d'Azur, France, was among those aboard the plane that crashed. (Facebook)

The plane went down on Sunday afternoon near Les Bergeronnes after taking off from Long Lake near Tadoussac, about 200 kilometres northeast of Quebec City.

The Transportation Safety Board said the plane may have taken a nose dive.

Fire in cabin after impact

Pierre Gavillet, an air branch investigator, told CBC News the plane crashed into a rocky mountain.

"What we noticed at first sight is that there is not a horizontal trajectory that entered the trees. We have trees that are intact and we have a plane that is on the ground that crashed vertically, between the trees," Gavillet said, adding the aircraft was heavily damaged.

"There was a post-impact fire," he said. "There was a fire in the cabin area."

After further inspection on Tuesday, Gavillet said it seems clear the plane's engine was running at the time of the crash.

"We were able to validate that the motor was running just before the impact based on the marks left on the trees," he said. There are propeller marks that allow us to confirm that the propellers were turning."

Gavillet said his team was able to recover instruments, including a damaged GPS and speed indicator. He said it's possible those instruments could reveal the plane's trajectory when it went down.

Police said Desrosiers was an experienced pilot and the weather conditions on Sunday were optimal.

The plane, built in 1956, belonged to Air Saguenay. The airline said the plane had a new motor.

Air Saguenay routinely flies tourists around in the area, as well as people heading to hunting and mining camps.

This is the second time an Air Saguenay seaplane has been involved in a fatal crash. In July 2010, four of six people aboard a de Havilland Beaver died, in part because the pilot took off despite bad weather.

Plane crash Cote-Nord

This de Havilland Beaver float plane crashed Sunday afternoon in near Les Bergeronnes after taking off from Long Lake near Tadoussac, Que. (TSB)

With files from the Associated Press