DENVER -- Police in Commerce City are trying to identify human remains found by a fisherman along the Burlington canal.

Officers searched the area Monday with a bloodhound and found more human remains including a human pelvis, femur bone and a tibia or fibula bone.

The remains have been turned over to the coroner who estimates it will take up to three weeks to determine the cause and manner of death. The bones will also be examined for DNA – a process that could take up to two months, said Lt. Mike Saunders of the Commerce City Police Department.

Police also said they were looking into any open missing person cases to try and identify the remains.

"There are a lot of scenarios that we're looking at," said Saunders. "One, is it a transient who died of natural causes and somehow ended up here? Or are we looking at foul play?"

The canal is just a few feet from the South Platte River bike path. Several bicyclists saw the police activity and stopped to ask what was going on.

When told they were retrieving human remains, John Gavina shook his head in disbelief.

"That's very unusual because this is a fairly low crime area, believe it or not," Gavina said. "Nothing ever goes down here."

"There's a possibility that work crews uncovered the remains while dredging the canal several months ago, but didn't notice at the time," Saunders said.

Commerce City police have cleared the scene, and water has been restored to the surrounding area, Saunders said Tuesday.

Anyone who has information about the possible identity of the remains or the investigation should call the Commerce City Police Department at 303-227-8840.