A TEXAS state trooper has been placed on administrative leave for violating police procedures after a video showed him confronting a motorist, who was later found dead in a police cell.

The video shows Brian Encinia trying to pull Sandra Bland out of her car, before drawing his stun gun and threatening her for refusing to follow his orders during a traffic stop.

She was found dead in a cell days later, but police claims that she hanged herself with a plastic rubbish bag are disputed by her family and supporters.

The video, posted on Tuesday by the Texas Department of Public Safety, shows the trooper stopping Ms Bland for failure to signal a lane change.

After handing her a written warning, he remarks that she seems irritated, which she confirms, saying that she had changed lanes to make way for the trooper’s car.

The conversation turns hostile when the officer tells Ms Bland to put out her cigarette and she asks why she can’t smoke in her own car.

He then orders Ms Bland to get out of the car and, when she declines, tells her she is under arrest.

Her refusals bring a threat to drag her out by the trooper who takes out what appears to be a weapon, saying: “I will light you up.”

When she does get out of her car, the officer handcuffs her and Ms Bland screams that he’s about to break her wrists and complains that he has knocked her head into the ground.

Mr Encinia testified that he was kicked, causing him to use force “to subdue Bland to the ground.” He then arrested her for assault on a public servant.

Texas Department of Public Safety director Steven McCraw said that the officer had been suspended for violating police procedures and the department’s courtesy policy.

“Regardless of the situation, it doesn’t matter where it happens, a DPS state trooper has got an obligation to exhibit professionalism and be courteous … and that wasn’t the case in this situation,” he said.

Ms Bland’s family and local clergy have called for a Justice Department probe and an independent autopsy has been ordered.