The Securities & Exchange Commission of Brazil (CVM) has rejected a settlement deal in an insider trading case involving JBS S.A. and its majority shareholders, Wesley and Joesley Batista, saying it “could be the most serious case of improper use of privileged information and price manipulation in the history of Brazil’s securities market.”

According to Reuters, the proposed deal involved an offer from JBS, the Batistas and related companies to pay 184.5 million reals ($45.4 million) in six quarterly installments.

In October 2017, the Federal Prosecutor's Office in São Paulo, Brazil, officially charged the brothers and business owners for insider trader trading that occurred prior to them signing a plea deal in May 2017. Both brothers were jailed, with Wesley serving a five-month sentence and Joesley serving a six-month sentence.

At the time, the prosecutor said Wesley and Joesley worked together to reduce paper losses and profit from the purchase of American currency, taking advantage of inside information and, as a consequence, manipulating the stock market.

The prosecutor’s office said the brothers, who both have deep knowledge of the business world, knew that the plea bargain would have two consequences: JBS shares would fall, and the U.S. dollar would rise.

Calculations suggest that the accused parties may have made more than 600 million reals ($147.8 million) from the insider trading, CVM said. As such, it rejected the settlement deal due to the severity of the allegations, Reuters reported.