Eight employees of Brazilian mining company Vale S.A. have been arrested over January's deadly dam collapse.
Since the disaster on January 25, the company has also lost a quarter of its market value — nearly $19 billion.
The disaster claimed upwards of 84 lives, with 276 still unaccounted for.
According to prosecutors in the mining state of Minas Gerais, police are also carrying out 14 search warrants as part of the probe.
The arrests and search warrants targeted employees of Vale as well as employees of German auditing firm TUV SUD, which had certified the dam as stable.
The latest warrants come after five Vale and TUV SUD employees were arrested last month, but were released by a higher court ruling on February 5.
Vale confirmed the arrest warrants on Friday and said it was co-operating with the investigation.
Among those arrested was Vale's Alexandre de Paula Campanha, who was involved in certifying the dam.
Also arrested was his colleague Helio Marcio Lopes da Cerqueira, who allegedly had email correspondence about faulty monitoring equipment at the mine.
The Vale employees arrested on Friday were responsible for the security and stability of the Brumadinho dam and will be held in jail for 30 days.
In the weeks since the dam collapse, the focus has been on retrieving bodies from the muddy sludge swallowing the town of Brumadinho.
Relatives of victims who died after the dam burst began laying their loved ones to rest at the end of last month.
While Vale has reportedly pledged a donation of $38,856 to each family that lost a loved one, locals are apparently not interested in compensation.
As Brazil comes to terms with what could be the worst industrial accident in the country's history, pressure for Vale to take responsibility is mounting.
Prior to the incident, the company enjoyed global success as the fourth largest mining company in the world. Vale is also the second most-traded share in Brazil's stock exchange, making it a key player in the country's economy.
However, the company's been called into question before following the breaking of the Samarco dam near the city of Mariana in 2015.
At the time, the dam's collapse caused the deaths of 19 people and irreparable pollution of the entire Doce River basin.
More than 20 people were charged with crimes, including homicide, but were never brought to trial. Nor was anyone convicted or jailed.
This second Vale tragedy could force a long-overdue debate about the environmental effect of exploiting its natural resources.
Vale chief executive Fabio Schvartsman said on Thursday that the company's safety procedures had not worked. He also evaded questions about why Vale had not yet paid fines owed for the 2015 incident.
Mr Schvartsman told reporters the company was "a Brazilian jewel" that "cannot be condemned for an accident that happened in one of its dams — even though it was such a big tragedy".
His statement drew angry responses from Brazilian politicians, who will set up a congressional inquiry into Vale in coming days.