The inquiry will determine whether the state must reinstitute charges against 279 miners.
Miners say Deputy President Cyril Ramaphosa must take responsibility for the Marikana massacre.
Julius Malema has compared the Marikana community to the struggle fighters in Soweto.
Hundreds are expected to gather at the Koppie today to pay tribute to those who lost their lives.
16 August marks two years since the death of 34 Marikana miners at the hands of police.
Victims of the 2012 shooting will be remembered at a commemoration rally this weekend.