BHP Group suspended all operations at the Escondida mine in Chile on September 23.
The facility ranks as the world's largest copper mine.
A worker died during maintenance work involving a front-end loader, according to union representatives.
National mining regulator Sernageomin dispatched an investigation team to the site.
Operations will remain halted until regulators verify safe working conditions.
BHP has not provided a timeline for the restart of the mine.