Impala Platinum has announced that a worker has died at its number 11 shaft in Rustenburg, taking the death toll in South African mines to three in less than two days.
The employee is reported to have died after inhaling noxious gases.
Operations at the mine have not been suspended.
South Africa's National Union of Mineworkers has announced that two other mine workers have died, one at Gold Field's Beatrix Mine and the other at Harmony Gold's Kusasalethu mine.
About 165 mine workers died in South African mines in 2009.