The remains found Wednesday on this beach on Tyee Spit near Campbell River have been determined to be a skeletonized animal paw. (CBC)

Remains found in a running shoe near Campbell River on Wednesday belong to an animal, the B.C. coroners service says, describing the incident as a "reprehensible" hoax.

The coroners service made the statement Thursday, only a day after a witness described seeing "a foot in a shoe" on a beach near the community on B.C.'s south coast. RCMP also said Wednesday that the find appeared to be a human right foot in a size 10 running shoe.

"The coroners service, a forensic pathologist and an anthropologist have all examined the shoe and remains, and determined a skeletonized animal paw was inserted into the shoe with a sock and packed with dried seaweed," the coroners service said in a statement released Thursday.

"This is a very, very senseless and thoughtless act," chief coroner Terry Smith said Thursday. "Clearly it wasn't done with any thought or feelings of the families of these missing people."

Kirsten Stevens, left, and Sally Feast, whose loved ones were victims of a small plane crash near Campbell River, say the foot hoax was cruel. (CBC)

RCMP spokesperson Const. Annie Linteau said police are determined to track down the person or persons responsible for the hoax.

"It's a despicable act. We're certainly taking it very seriously and embarking on a whole new investigation — [a] public mischief investigation," she said.

Wednesday's discovery created undue anxiety for some Campbell River families whose loved ones were victims of a plane crash three years ago.

The small float plane took off from Tyee Spit and crashed near Quadra Island, which is about 10 kilometres away from where the remains were found Wednesday. Five people were on the plane and only one body was ever found.

"It's so cruel doing something like that," Sally Feast said of the foot hoax. Feast's brother, Arnold, was the pilot of the plane that crashed and he remains unaccounted for.

Kirsten Stevens, whose husband Dave died in the crash, said whoever pulled the prank didn't do it flippantly.

"They thought it out … It's unfathomable that anybody would have that kind of sick sense of humour or whatever it is that would motivate them to do this kind of thing," Stevens said.

5 human feet found still a mystery

Meanwhile, investigations into the genuine cases of human feet that have been found are ongoing, the coroners service said.

Feast said police have told her DNA tests of the first three feet found have not matched two of the plane crash victims but investigators are still waiting for results of DNA tests involving the other two victims.

The latest — a left foot — was found Monday, partially submerged in the water near Westham Island in Ladner. Delta police haven't said whether it belonged to a man or a woman.

A woman's right foot was found in May on the uninhabited Kirkland Island in the Fraser River — only a few kilometres away from the site near Westham Island.

Before that, three other right feet — all from men — had been found. In August 2007, feet were discovered on Gabriola and Jedediah islands and, in February 2008, another foot was found on Valdes Island.

All five feet were in socks and shoes.