Recent developments said that Brazilian mining firm Samarco was warned that one of its dams had a "severe" structural problems a year before the dams collapsed. However, the company seemed to ignore the warning, and did not take any precautionary measures to fix it, an engineer who worked on the dam disclosed.

Wall Street Journal reported that the mining giant received warnings of the dam's structural problems, but these were ignored. The publication also said that Brazil's TV Globo reported that it had obtained documents that showed that consultants hired by the mining firm said that the dam's safety was compromised. These documents were date more than two years ago, the report added.

According to The Australian, the engineer who worked on the dam, Joaquim Pimenta de Avila, said he was consulting for the mining firm back in September 2014. The engineer said that he inspected a crack in the Fundao waste-storage facility. He told the Brazilian mining firm that the crack in the dam indicated the initial signs of a break. He urged Samarco to monitor the crack and recommended that the Fundao dam be reinforced with a buttress.

The Fundao dam collapsed about 14 months later, releasing sludge that destroyed a nearby village and killed at least 17 people. Brazil has called the dam burst the county's worst environmental disaster to date. The incident has also prompted a criminal investigation, and a $5 billion civil lawsuit by authorities against Samarco and its parent companies, Vale and BHP Billiton.

Samarco, however, disputed de Avila's claims, and said the company followed his recommendations. Company lawyer Mauricio Campos Jr. reported the company never received any warnings of an "imminent" rupture from its consultants.

Samarco added that "cracks and surges" can occur in any dam.

Pimenta de Avila is known in Brazil as a leading dam engineer. He was named a key witness in the criminal investigation of Samarco and several of its officials made by Brazil's Federal Police

Pimenta de Avila was hired by Samarco to design and oversee the construction of the Fundao tailings dam in the periods between 2008 and 2012. However, Samarco did not renew his contract when it expired, though they did hire de Avila for part-time consultation work from 2013 to 2015.

The mining firm said de Avila was aware of what was being done when it came to his recommendations and never protested. The engineer added that he wasn't responsible for the Funado dam after 2012 because Samarco chose to depart from his design.