Kahnawake Mohawk Peacekeepers are investigating after a human skull and bones were found near the Mercier Bridge on Monday.
The bones were found in a wooded area by a construction worker completing repair work on the bridge, off Montreal's south shore.
"There was some debris, some trees, some small saplings that had been placed to cover the remains," KMP investigator Warren White told CBC News on Tuesday.
The bones were sent to the provincial police forensic lab for identification, said White. The process is not expected to be completed before Thursday.
The area is being treated as a crime scene, but White said it is too soon to link the remains to any missing persons' cases.
"Nobody wants to say that it is a missing girl that we have from our community but I mean there is always that possibility," said White.
Later this month will mark the fourth anniversary of the disappearance of Tiffany Morrison.
The woman was 25 when she was last seen in the Mohawk community.