A spokesman for Transportation Safety Board says the plane, a Piper Aztec twin-engine light aircraft, likely went down Thursday evening.
There were no witnesses to the crash, about two kilometres outside the small Inuit village on the northwestern shore of Ungava Bay in Quebec's Nunavik region.
A first emergency distress signal was captured by satellite late Thursday and the Canadian Forces base in Trenton, Ont. dispatched a Hercules aircraft to the area.
Local police and Canadian Rangers were able to find the wreckage around noon Friday.
Quebec provincial police spokeswoman Audrey-Anne Bilodeau says the coroner has not confirmed the three deaths.
"There were three people on board found with very serious injuries but we have not received confirmation that they have died," Bilodeau said.