(Reuters) – Prosecutors are planning to file criminal charges against Brazil’s miner Vale SA and its employees over the collapse of a mine-waste dam in January that killed hundreds of people, the Wall Street Journal reported, citing the lead investigator.

Investigators have gathered enough evidence to affirm that Vale employees involved in the mine operation knew the dam was unsafe, the report said, quoting Jose Adercio Leite Sampaio, the prosecutor heading the probe.

“At this point, we know that the operational side knew [that the dam was at risk of collapse], but did Vale’s directors know?” Sampaio said in an interview with the Journal.

The charges for crimes related to the disaster could include murder, manslaughter, environmental damage and false representation, according to the report.

“It is necessary to wait until investigation is completed. Vale continues cooperating fully with the authorities to ascertain the facts related to the dam breach,” Vale said in response to a Reuters query.

“The issues identified in the audits have been addressed under the guidance of the auditing firms.”

In March, Vale estimated it would sell up to 75 million tonnes less iron ore this year, after several mines were halted following its second deadly dam burst in less than four years.