The investigation is related to an initial administrative probe opened on Jan. 28, when CVM started looking into potential violations of securities laws over the incident.

The securities body, which has the power to impose fines and bar executives from working at listed companies in Brazil, added the investigation does not concern environmental issues, which it said other agencies are looking into.

Vale did not immediately respond to Reuters’ request for comment on the matter.

Vale shares have fallen over 14% so far in 2019, after climbing almost 32% in 2018.