Police in Benoni on Sunday discovered the bodies of seven people believed to be illegal miners dumped in an open veld near a mine shaft.
Police Spokesperson Colonel Lungelo Dlamini says it is suspected that the men were shot and killed elsewhere before their bodies were dumped in the veld.
He says they believe the men could have been killed about three days before being discovered, since the bodies already started to decompose.
Dlamini says it is expected that the victims are foreign nationals who are involved in illegal mining in the area.
The names of the victims are still unknown and the investigation continues.