RIO DE JANEIRO/BRASILIA (Reuters) – Brazilian authorities investigating the fatal January collapse of a dam owned by miner Vale SA have recommended the removal of the firm’s chief executive and several other high-ranking employees, national media reported on Saturday.

State and federal prosecutors have recommended the “immediate removal” of CEO Fabio Scharvtsman and three other executives from “any functions or activities” at the firm, newspaper Folha de S.Paulo said, citing the document in which the recommendation was made.

Investigators also recommended the removal of Vale’s head of ferrous minerals and coal, Peter Poppinga, planning director Lucio Flavo Gallon Cavalli and Silmar Magalhaes Silva, the head of a geographic division at Vale, as well as three managers and two technicians, the paper said.

The document, sent to Vale, gives the company 10 days to respond. If the firm does not remove the people in question, prosecutors may request that the people be imprisoned, Folha reported.

In comments to Reuters, Vale said it would examine the recommendation within the 10-day timeframe provided, and emphasized that all executives were cooperating with the investigation.

The recommendation comes slightly over a month after a tailings dam broke at Vale’s Corrego do Feijao mine in the interior Brazilian state of Minas Gerais, likely killing over 300 people and releasing massive amounts of toxic sludge.

It was the second deadly burst at a Vale-linked tailings dam in Minas Gerais in four years.

In the weeks since the burst, documents have emerged showing that Vale knew the dam had an elevated risk of rupture and that inspectors felt they were under pressure to certify the structure as safe.

This week, Folha reported that a Vale manager had told executives that the integrity of the structure had worsened, though the company vigorously denied the report.