The victims have not been named.
Tremblay told The Canadian Press on Monday the flight was only supposed to last 20 minutes.
The Sureté du Québec was first alerted on Sunday afternoon to a missing locator device on the Air Saguenay plane.
Air Saguenay Vice President Jean Tremblay said the pilot was highly experienced with more than 6,000 hours of flying experience over 14 years with the airline.
Four Britons are reportedly among six people who have been been killed in a light plane crash in Canada’s Quebec province.
Although those on board have not been officially identified, CBC News is reporting the pilot’s name as Romain Desrosiers, and that 28-year-old Emilie Delaitre from France was one of the passengers. It wasn’t windy and visibility was clear on Sunday.
According to Le Journal de Quebec, a distress call was heard before it crashed into the mountainside.
Several causes are being considered, including adverse weather conditions at the time of the crash.
The small Beaver aircraft operated by Saguenay Air had taken off from a strip at Tadoussac on the north shore of the Gulf of Saint Lawrence, about 500 kilometres northeast of Montreal. The region is popular with whale watchers.
Their bodies are reported to have been handed over the coroner’s office. “It’s very hard for the Air Saguenay team”.
Inspectors from the Transportation Safety Board are also heading to the area, which is the standard routine for every aviation crash.