Police are combing through missing person reports in Ontario and New York state to try and determine the identity of a woman whose torso was pulled from the Niagara River earlier this week.

Niagara police Insp. Jim McCaffery said it is critical to identify the victim to bring closure to her family and determine what led to the death.

“It’s also important to bring those responsible for this crime to justice,” McCaffery said during a press conference on Friday.

He said police are looking at 20 missing person cases, but investigators expect that number to grow.

Police have not been able to determine whether the torso came from the Canadian or American side of the Niagara River.

“It’s fast moving water, so I think the main thing we’re going to have to do is determine identity,” said McCaffery. “It’s taken longer than usual but the identity is critical.”

McCaffery said post-mortem examinations on the body are continuing and Niagara police are working with the Centre of Forensic Sciences in Toronto and the chief coroner’s office to identify the victim.

Police estimate the body was in the water for four to 10 days before it was recovered.

Investigators are appealing to the public for help in identifying the victim, who they say is Caucasian, had a pierced navel and showed signs of having had at least one caesarean section. She also had a tubal ligation procedure.

“I believe the information we’ve provided will jog someone’s memory,” said McCaffery. “There is someone out there, I think, with that information which can (help) us.”

A tourist first spotted the floating torso below Niagara Falls while riding on the Maid of the Mist boat on Wednesday.

Investigators have not recovered any limbs or the woman’s head.

According to investigators, the discovery is not related to the ongoing investigation into the death of Hua Guang Liu, whose body parts were discovered in two Toronto-area parks in recent weeks.

With files from CTV Toronto’s Tamara Cherry