Rapaport says the model should guarantee that government diamond revenue provides vital infrastructure to the communities where the diamonds are found.
Opponents to mining projects in South Africa are often harassed, threatened and sometimes even killed, according to a report by a group of human rights advocates including Human Rights Watch.
The Canadian miner's second-largest investor, Waterton Global Resource Management, has filed a lawsuit against the base metals producer in a bid to constrain its ability to solicit proxies.
The probe was prompted by a petition filed by two uranium mining companies, complaining that subsidized foreign competitors have caused them to cut capacity and lay off workers.