A fifth human foot in a year has washed ashore off the coast of British Columbia, and this time it is a left one.

Police said two people out for a walk spotted the left foot floating in water off Westham Island on Monday morning.

Delta Police Const. Sharlene Brooks said officials are working with the B.C. Coroner's office to see if this foot is linked to any other partial remains recovered in the province.

Westham Island is at the mouth of the Fraser River, about 15 miles south of Vancouver.

"A passerby noticed a shoe floating in the water, pulled it in and notified police," Brooks said. "We're treating it as a criminal investigation."

While the similarities to the other found feet is strong, she said there is no indication this foot is related to the other cases.

"We're certainly not discounting the possibility that this may be linked to the other recovered feet, but it's just too premature and very speculative for us to even entertain that right now," she said.

The last foot was found May 22 on Kirkland Island in the Fraser River, about one mile away from Monday's discovery.

The first in the series was found nearly a year ago on Jedidiah Island in the Strait of Georgia. Within days, another right foot was found inside a man's Reebok sneaker on nearby Gabriola Island. The third was found in the same area, on the east side of Valdez Island in early February.

The origin on any of the remains is still unknown.

"This might take a long time," Brooks said. "This is not CSI." She said in order to identify the foot, other remains from the body or identifying material such as DNA would be needed. "It's going to be pretty difficult."

The Royal Canadian Mounted Police has said there's no evidence the feet were severed or removed from the victims' legs by force.

Curtis Ebbesmeyer, an oceanographer based in Seattle, Washington, said when a human body is submerged in the ocean, the main parts like arms, legs, hands, feet and the head are usually what come off the body.

He said his theory is that the feet came along as a result of an accident that might have happened up along the Fraser River, that washed down and spread out along the Straight of Georgia.

Ebbesmeyer said when the third foot was found the feet could have drifted from as far as 1,000 miles away. Ebbesmeyer said the feet could have been severed or detached from their bodies on their own.