The B.C. Civil Liberties Association is calling for an independent investigation into allegations an RCMP officer in Williams Lake, B.C., assaulted a 17-year-old girl.

Martina Jeff says her teenaged daughter, Jamie Haller, was punched in the face by an RCMP constable while she was handcuffed in the back of a police car.

Jeff said the incident happened on Sept. 10 after Haller had called the RCMP for assistance.

"I saw Jamie on the ground, crying and handcuffed," Jeff said. "I got out and ran towards her. She was having a panic attack. She is very small and has never been in trouble with police before."

Haller said she was mistakenly arrested and was kicking at the inside of the car windows, trying to get the attention of her mom, who was nearby.

"There's two cops in the front, and ... one cop was sitting on my legs and the other cop was holding my head back and was punching me," Haller said. "The cop was punching me on this side, and I know he punched me more than six times."

Jeff witnessed the incident from a few feet away.

"I heard one [officer] say, 'Keep kicking and you’ll see what happens,'" Jeff said.

"He put his whole upper body in the car and started punching … When I looked in the car I saw my daughter. Her face started swelling really bad. There was blood coming down on each side of her mouth. She was handcuffed, with her hands behind her back."

The BCCLA is calling for an immediate and independent investigation of the incident by, at a minimum, a senior officer from outside the Williams Lake RCMP detachment.

"The community needs confidence that these serious allegations will be investigated fully, promptly and as impartially as possible under our current system. If wrongs were committed, the public wants to know that they will be dealt with in accordance with the law — whether those involved are employed as law enforcement officers or are members of the public," said BCCLA president Robert Holmes.

"The community needs to trust that when someone calls 911 for the police, they will be treated with respect and not end up in hospital because of injuries sustained due to police actions."

Haller was released the next morning without charge and alleges she did not receive any medical attention.

The teen said she was unable to work at her job at a fast food outlet because of the bruising on her face and had to take a week off school due to injuries to her eye that affected her vision.

However, RCMP Sgt. Warren Brown said the accounts of police officers on scene differ dramatically from Haller's account, and police are recommending the teen be charged with assaulting a police officer.

Brown said he has asked a senior officer at a neighbouring detachment to investigate.