Lac Berthé is located 15 kilometres northwest of the Manic-5 hydro dam.Lac Berthé is located 15 kilometres northwest of the Manic-5 hydro dam. (Google Maps)

Quebec provincial police divers continued their search on Monday for two men following a place crash 200 kilometres north of Baie-Comeau.

The men left Baie-Comeau aboard the float plane on Tuesday en route to a fishing camp and were last heard from on Thursday night.

After the two men, aged 69 and 78, did not return as planned on Friday, a relative set out in his own plane to look for them.

The man was able to locate debris from the plane on Lac Berthé, 15 kilometres northeast of the Manic-5 hydro dam, said Sgt. Patrick Lowe.

"He heard the emergency locator transmission," said Lowe.

A piece of the tail was found floating on the lake, but searchers have so far been unable to locate the body of the plane.

On Monday, police were using sonar to search the bottom of the lake.

"We're still hoping to find those guys alive, but for right now we're trying to locate the plane," he said.

Police said it is not clear what caused the crash.