In the US, footage from a dashboard camera has been released, showing an altercation between a white Texas police officer and a black woman, who was later found dead.

Sandra Bland (28) had been pulled over for changing lanes without indicating - a minor traffic offence.

The white policeman who pulled her over agressively attempts to pull her from the car after they argue over his demand that she step out of the car.

At one point he pulls his tazer out and threatens 'to light her up'.

Once out of the car, Sandra Bland can be heard complaining that the officer has knocked her to the ground and slammed her head off the pavement.

Three days after being taken into custody, she was discovered dead in her cell.

It was thought she had taken her own life, but after protests from her friends and family authorities have opened a full investigation.

The trooper involved has been put on desk duty, pending the outcome of the investigation.

Footage of the incident, which happened in Prairie View, Texas, has been released. See an excerpt here:

The full hour-long footage is available to view on the Texas Department of Public Safety YouTube account.

In a statement yesterday, Director Steven McCraw of Texas DPS said they had involved the FBI in the case, “This team of investigators is committed to conducting a thorough and impartial investigation. When the Texas Rangers and FBI investigation is complete, it will be turned over for review by the District Attorney, who has indicated it will also be brought before a grand jury.”

"Pending the outcome of the investigation, Trooper Brian Encinia, who conducted the traffic stop, has been assigned administrative duties. Once the investigation has concluded, any violations of DPS protocols or procedures will be addressed."