AKIPRESS.COM - South Carolina officials have released a new video showing the moments before a US police officer shot dead an unarmed black man in the back.

The footage shows Walter Scott's car being pulled over and Officer Michael Slager asking for his paperwork. After Mr Slager returns to his police vehicle, Mr Scott opens his door and runs, leaving a passenger in the car.

Mr Slager was arrested on murder charges after another video showed him shooting at Mr Scott as he fled. The newly released video from the officer's dashboard camera shows Mr Slager pulling over Mr Scott's Mercedes sedan due to a broken tail light, and asking for his driving licence and registration.

Mr Scott explains that he is in the progress of purchasing the vehicle and does not have the correct paperwork with him. Although the video does not capture Mr Slager firing eight shots, gunshots and shouting are heard off-screen.

Video was uploaded on YouTube by ABC News.

Later in the video, another police officer questions the passenger in the car and releases him. Lawyers for Mr Scott's family told CNN that they are looking for the passenger.

After the first video of the incident emerged on Tuesday, protesters held rallies in North Charleston, chanting "no justice, no peace". They are the latest protests about police use of lethal force, which began after the killing of Michael Brown, a teenager in Ferguson, by a police officer who was not charged for his death.

Feidin Santana, who filmed the first video on his mobile phone, said he turned over the footage after reading the police report's description of the killing.

"It wasn't like that, the way they were saying," Mr Santana said. Mr Slager, who is being held in jail without bond, was fired on Wednesday from the North Charleston Police Department.

It has also emerged that Mr Slager had a prior complaint made against him about using force. Police are re-investigating Mr Slager's use of a stun gun on Mario Givens in 2013. Mr Givens said Mr Slager had pushed into his home after coming to his door.

"Come outside or I'll 'Tase' you,'" he quoted the officer as saying, adding he raised his arms over his head but was then stunned in the stomach. Mr Slager was investigating a complaint against Mr Givens' brother and apparently mistook Mr Givens for his sibling. Charges were dropped and Mr Slager was exonerated by a police investigation into the incident, reports BBC.