Quebec's provincial police and the workplace health and safety board are investigating the company in charge of a gravel quarry where the bodies of two employees were buried in a landslide on Tuesday.

Jacques Nadeau, spokesman for Quebec's workplace health and safety board (CSST), said it will take about six months before the board's investigation is complete.

"We want to make sure that we can maybe learn something from the accident and also make sure that in the future that doesn't happen again. So, all the aspects surrounding the accident will be checked. The background of the company too," he said.

Louis Marchand, the president of Maskimo Construction, said the incident is a major event for them and they will co-operate with the investigations over the following weeks.

"We offer our deepest condolences to the employees' families and relatives. This accident is an important ordeal for our company," he said. "We will actively take part in all of the investigations that will help us determine the cause."

The bodies of two workers who were swallowed by rubble after a landslide at a L'Épiphanie, Que., quarry were found after four continuous days of searching.

Quebec provincial police said the body of Daniel Brisebois, 54, was located at around 12:20 p.m. on Saturday.

Marie-Claude Laporte's body was found at about 6:20 p.m.

Search crews had been searching for the two workers since Tuesday. Their vehicles were trapped in huge mounds of loose gravel at the bottom of the pit.

A third worker whose vehicle also fell into the quarry was rescued by a provincial police helicopter on Tuesday, within hours of the collapse.

In 2004, an accident at the same quarry killed one man and injured another.