VANCOUVER -- An independent police investigation has been launched into allegations that a police dog bit a 12-year-old Prince George girl, leaving her with extensive wounds to her leg.

Watchdog groups says the incident in May was not the first time service dogs have been used on teens and children, and they're urging RCMP to ensure it doesn't happen again.

The Pivot Legal Society, the Carrier Sekani Tribal Council, and the Union of B.C. Indian Chiefs, along with the girl's family, have sent a letter to the provincial director of the RCMP police dog service, calling on the force to avoid using police dogs unless the youth "presents a clear threat of death or grievous bodily harm to themselves or others."

The girl's mother said in a telephone interview Wednesday that her daughter had fled the scene of a fight after macing two other kids in self-defence. When the police found the girl, her mother said she shouted out that she was only 12 years old, yet the RCMP handler still released the dog.

The child's mother, who did not want her name published, maintains that the Mountie knew the girl's age.

"I was told, from what my daughter said, that her name was brought up because other people (at the scene) knew her name," the mother said. "I believe that the RCMP knew who they were looking for, and that she was only 12."

She said her daughter was hiding in a nearby building when the police dog and handler eventually found her.

"She was hiding in a box and when she saw the police dog, she tried yelling out that she's only 12 years old before they let the dog loose on her," the mother said.

She said the dog jumped onto the box and bit her daughter's left leg after she fell out.

She also alleged that after the police took her daughter to the hospital to be treated for her bite wounds, they kept her in a jail cell until early next morning.

The family lodged a complaint with the RCMP and the New Westminster Police are investigating the incident. Sgt. Diana McDaniel of the New Westminster Police said she cannot confirm the family's allegations because the investigation is ongoing.

The groups calling for a policy change said a Surrey youth was also bitten in the face earlier this year after allegedly stealing an energy drink, and a 12-year-old in Vancouver was bitten by a police dog.

The RCMP said in a statement released last month that officers responded to a call in May about an alleged attack on two people who had been blasted with bear spray at a Prince George carnival.

A police dog and handler tracked a suspect to a locked compound where a can of bear spray was found and where the dog bit the suspect on the leg, the statement said. It noted the suspect turned out to be a 12-year-old girl.

B.C. RCMP said in most cases where police dogs are employed, the age and identity of the suspect is unknown.

"Expecting police to know the age of fleeing suspects shows a lack of understanding of policing, as does any belief that young people can't be dangerous or pose a threat," Sgt. Rob Vermeulen in an email response to questions.

"Where it IS known that the offender is a young person, and the offence/threat is minor in nature, RCMP handlers in the province have been advised not to pursue."

Vermeulen added that the level and type of force used on a suspect depends on the suspect's behaviour.

"Service dogs do not 'decide' if they are going to bite a person," he wrote. "They react to situations or scenarios that are taught to them starting when they are a puppy and reinforced throughout their training and operational service."

The girl's mother said her daughter suffered bruises and scratches from the incident, and received 20 stitches for her bite wounds.

"She couldn't move for about a week or two, so she was a little bit depressed about it," she said.

"It's still kind of hard to talk about it right now because she's obviously going to have these scars for the rest of her life."