Police say they suspect that there are more illegal miners at the Sheba gold mine in Barberton, Mpumalanga.
This after about 400 miners were arrested at the mine on Friday.
Police say most of them are undocumented migrants and will be charged with the contravention of the Immigration Act.
The arrests were made during the police-led raid-Operation Val Umgodi, whose aim is to combat illegal mining activities.
Provincial police spokesperson Donald Mdluli says, There are those other ones who went deeper. They didnt come up. They instead decided to go deeper. To us this means that we need to reassess and also get mine security to join us and other law enforcement agencies. Its a very costly exercise.