The SA Human Rights Commission will investigate the conduct of the police, Lonmin, and local government in the killings at Marikana, it said on Friday.
"[We] have requested the Legal Resources Centre (LRC) to gather evidence from victims, suspected perpetrators, forensic pathologists and experts," the commission said in a statement.
Thirty-four miners were shot dead on 16 August when police tried to disperse striking workers at Lonmin's platinum mine in Marikana, North West.
A Cape Town-based NGO contended that national police commissioner Riah Phiyega and the police violated the miners' right to life, as enshrined in the Bill of Rights.
The SAHRC would consider the culpability of the SA Police Service "in their conduct with regards to the incidents which took place at Marikana, and the conduct of the police in the area around this time".
It would examine claims of "corporate malpractice" by Lonmin. This related to allegations on the water quality in the area, Lonmin's recruitment practices, the living conditions of the workers, and compliance with mineral and environmental legislation.
The SAHRC would investigate the local government's failure to deliver services in and around Marikana.
Based on evidence collected by the LRC team, headed by human rights advocate George Bizos, the SAHRC said it would decide whether to take legal action.
The LRC'S evidence would form the basis of the SAHRC's presentation to the presidential commission of inquiry, chaired by retired Supreme Court of Appeal judge Ian Farlam.
"In responding to this complaint, the SAHRC aims to help contribute to justice for the Lonmin miners, their families and all those who continue to experience such violations of their Constitutional rights," the commission said.