This is the tough justice moment police drag a suspected drug dealer down the road handcuffed to the back of a patrol SUV.

The video footage, filmed in Cape Town, South Africa, shows officers cuffing the suspect to the back door of the vehicle surrounded by an angry mob.

Moments earlier, according to local media, the suspect had been arrested in possession of cocaine and was being taken away for questioning.

But, the police said, as the angry crowd began to pelt them with rocks, they had to escape quickly.

This astonishing footage shows the suspect dangling by his left arm with his heels dragging along the tarmac as the car takes off down the road at speed.

The patrol car can be seen going fast enough to easily leave behind members of the crowd giving chase on foot.

The footage caused outrage after it was shared online, with the Independent Police Investigative Directorate (IPID), the country’s internal affairs agency, announcing that it was investigating the incident.

Directorate spokesperson Robbie Raburabu said they had not yet questioned the officers.

He explained: “Police officers will only be approached after witnesses have been interviewed.”

But the incident was slammed by human rights activist Zona Morton.

She told local media: “The suspect’s human rights were violated by the SAPS [South African Police Service] cuffing him and dragging him behind their vehicle.”

The investigation is ongoing.