Quebec provincial police received a 911 call at 4:10 a.m. ET on Friday from a residence in the town, which is located on the south shore of Lac Saint-Jean.
Jean Tremblay, a Sûreté du Québec officer, said the baby was found without vital signs, but provided no further details.
Tremblay wouldn't give the age of the baby, but said it was a newborn.
He said the case is considered a "criminal investigation," and police are meeting with an "important witness."