Eight employees of the Brazilian mining giant Vail were arrested during a criminal investigation into a violation of the dam last month.
The gap of the Feijao dam used to collect waste has killed at least 166 people in Brumadinho. 147 still missing
Four people from the German consulting group Tüv Süd were also detained.
Arrests were held in Sao Paulo, Rio de Janeiro and Belo Horizonte.
Two of the arrested are executives of Vale. All of them will be questioned by investigators in Belo Horizonte.
Tüv Süd conducted an audit last September when it discovered that the dam complies with legal requirements.
But earlier this week, an internal report from Reuters reported that the Brazilian mining company knew that the dam was under threat as it was reported that the site violated the guidelines for months before it collapsed.
The iron ore miner said that the report was misleading because there was no evidence of imminent risk.
The dam of the dam was the second major mining catastrophe in the region since 2015, when the neighboring dam belonging to Vale fell.
Daniel Gallas, Corresponding Member of South America
After the Vale Crash of 2015, the Brazilian authorities were sharply criticized for being too slow and self-satisfied. Nobody has been convicted for this accident.
This time judges, investigators and politicians show a different attitude. This month, 17 people were detained for interrogation. The court orders suspend some of Vale's most profitable operations and freeze the assets of the company.
Executive power was evaded when they questioned why the company had not yet paid a lot of fines in relation to the disaster of 2015. an accident that occurred in one of its dykes – although it was such a big tragedy ", having caught angry answers from legislators. Politicians will create a congressional call for Valais in the coming days. Still stricter legislation on extraction of minerals
Read more from Daniel: From the pride of Brazil to the most hated company
It is not yet known what caused the collapse of Brumadigno, but experts believe that liquefaction was to blame. Liquid is a process in which a solid material, such as sand, loses strength and behaves more like a liquid.
The company lost a quarter of its market value – or nearly $ 19 billion – after the disaster of January 25th.