The four Britons killed in an air crash in Canada were a family on the last day of their sightseeing trip, according to reports.

The parents, both 40, and their two teenage daughters, aged 14 and 17, were killed when their light aircraft crashed into a mountainside 20km (12 miles) from Tadoussac where they were staying, according to the Journal of Quebec.

The family had booked into the hotel for three nights and were due to leave on Monday, but were killed the day before, the newspaper reported.

The impact was so severe nobody could have survived, and pilot Romain Desrosiers and French passenger Emilie Delaitre also died in the accident, according to the newspaper.

Canadian authorities have not named the British family and warned the investigation into what caused the accident could take some time.

Foreign Secretary Philip Hammond offered his condolences to the family of those killed in the crash, which happened on Sunday afternoon in the Les Bergeronnes area of Quebec province.

Mr Hammond said: "This terrible incident has taken the lives of all on board, including four British nationals. My thoughts and sympathy are with their family and friends at this difficult time.

"Our High Commission in Ottawa is in close contact with the Canadian authorities and we are providing consular assistance to the relatives of those who were killed."

A picture on the Transportation Safety Board of Canada's website shows the wreckage of the red and white Beaver aircraft on a rock edge next to thick woodland.

The plane, operated by Air Saguenay, took off from Lac Long in Tadoussac on a routine sightseeing flight before crashing on Sunday afternoon.

An Air Saguenay official said the flight was supposed to last 20 minutes and flying conditions at the time were "excellent".

Although the weather was good when the flight took place, cloud and rain significantly affected efforts to access the steep and densely wooded area.

Police said the bodies of all six people had been found, while investigators from the Transportation Safety Board of Canada were sent to the scene.

The bodies were moved to a laboratory on Tuesday for forensic tests.

Jean-Marc Ledoux, a regional manager with the Transportation Safety Board of Canada, said it would take time before the cause of the crash is known.

He said: "We're taking the time to conduct a thorough investigation, and because it was a smaller plane there was no flight data record, which will obviously make matters more difficult.

"There will always be different factors that contribute to these incidents.

"It is always hard to say how long these investigations will take."

He was unable to confirm the identity of those on board as victims' next of kin may not have been contacted.