I would say that it's both.
A government of course has the obligation, both under its domestic criminal law and under international human rights law, to investigate all allegations of abuses like gang rape, beatings, or killings. But especially in this case, as Mr. Albin-Lackey mentioned, where the government has literally no capacity and apparently no willingness to actually investigate transparently and comprehensively these allegations, the company itself has taken on a state responsibility in this particular area and has the obligation to investigate independently the allegations that have been made.