South Africa shock as 'police dragging' video man dies

South Africa's police watchdog is investigating the death of a Mozambican taxi driver who was allegedly handcuffed to the back of a police van and dragged through the streets.

Video footage taken by a bystander of the incident, near Johannesburg, has been shown in the local media.

A spokesman for the Police Investigative Directorate said he was "shocked" by the footage.