Eight South African policemen have been charged with the murder of a taxi driver who was bashed, tied to the back of a van and dragged along the road in Johannesburg.

Mozambican taxi driver Mido Macia, 27, was found dead in detention with signs of head injuries and internal bleeding, according to an initial post-mortem report released by the Independent Police Investigative Directorate (IPID).

Mido Macia, pictured with his sister Melida, was tied up and dragged behind a police van. ( AFP )

The video-recorded treatment of the Mozambican taxi driver has further damaged the reputation of the police force in South Africa, where more than 1,200 people a year die in custody.

"They will answer to a charge of murder when they appear in court on Monday," IPID spokesman Moses Dlamini told Reuters.

The video of Tuesday's incident shows Macia scuffling with police, who subdue him.

He is then bound by his arms to the back of a van before the vehicle drives off in front of scores of witnesses in the east Johannesburg area of Daveyton.

"We would like to assure the country and the world that what is in the video is not how the South African Police Service in a democratic South Africa goes about its work," Commissioner Riah Phiyega told a news conference.

Before the arrests, she said the eight officers had been suspended and the station commander would be removed from his duties.

Macia's sister-in-law, Lindiwe Engwengwa, was among a small crowd of protesters who gathered outside the police station where he died in the holding cells.

"Really I am devastated [by] what happened. I'm really shocked, I'm really disappointed," she said.

"What they did to my in-law, I didn't expect such a thing.

"I thought they were the people to help us, to protect us but now are the people who are killing us.

"I'm happy however they are showing it on the TV, I'm very happy so that they can see, the others, how cruel they are."

Relatives of Mido Macia hold up newspapers showing coverage of the incident. ( AFP: Alexander Joe )

South Africa's president Jacob Zuma and opposition politicians have condemned the incident, which was broadcast nationwide on Thursday.

"The visuals of the incident are horrific, disturbing and unacceptable. No human being should be treated in that manner," Mr Zuma said.

Police said they had detained Macia after he parked illegally, creating a traffic jam, and then resisted arrest.

The incident is the latest in a series of scandals to hit South Africa's police force, already dogged by a reputation for brutality, corruption and incompetence.

The lead detective in the murder case against Olympic and Paralympic star Oscar Pistorius was removed from the investigation last week when it emerged he was facing seven attempted murder charges for allegedly opening fire on a minibus full of passengers.

Police also shot dead 34 striking workers at a platinum mine in August last year - the deadliest security incident since apartheid ended in 1994.

Outrage: A police car faces protesters and it drives outside the Daveyton Police station east of Johannesburg. ( Reuters: Siphiwe Sibeko )

ABC/Reuters