CCTV footage showing an American police officer tasering a 14-year-old girl in the crotch has emerged online after a lawsuit was filed against the officer.

Keshana Wilson, from Allentown, Philadelphia, claims the officer, Jason Ammary, arrested and tasered her without provocation.

The girl who's still in high school says the officer pushed her against a car from behind without identifying himself.

The video clearly shows Ammary aiming the taser at Miss Wilson following a struggle, however, the video neglects to show what happened in the build-up.

Officer Ammary then stands back and fires his taser at the teenager's groin. Ammary, of the Allentown Police Department, claims that Wilson was resisting arrest and elbowed him in the face.

He also claims that he aimed for her crotch because Miss Wilson was using her back pack to block the taser, although in the video, it's clear she doesn't. Wilson can be seen raising her hands in cooperation seconds before he fires the weapon.

Richard J. Orloski, the attorney working on behalf of Keshana Wilson and her mother, Victoria Geist, said that the police officer in question used excessive force when the taser was fired.

However, Allentown police have accused the teenager of cursing, inciting a crowd and resisting arrest.