Petra Diamonds has resumed operations at the South Africa-based Koffiefontein mine after underground operations were suspended following the death of a miner on 3 January.
The equipment-related accident, which was not due to mining activity, took place at an underground workshop.
Mine management and the South African Department of Mineral Resources have conducted investigations.
Diamond production at the mine was not impacted by the 48hr closure.
The incident is the first death at a Petra Diamonds mining operation since 2004.