Brazil federal prosecutors have filed criminal charges against Eike Batista, accusing the fallen tycoon of market manipulation and seeking to freeze up to $1.5 billion reais ($641 million) worth of his financial assets and properties.
The Rio de Janeiro prosecutor's office said on Saturday it is charging Batista for deceiving investors with a "simulated" promise two years ago to invest $1 billion in oil company OGX, now known as Oleo e Gas Participacoes SA, if shares fell to a certain level. Batista failed to fulfill his promise, known as a put option, when the shares touched that level.
Read MoreThe downfall of Eike Batista
Batista is also accused of using privileged information on several occasions last year to make a profit of 236 million reais with the sale of company stock, the statement said. The charges against Batista could carry up to 13 years in prison.
A representative of Batista's EBX Group said the industrial group will not comment on the charges. Batista has repeatedly denied any wrongdoing in previous public statements on the case.
OGX filed Latin America's largest-ever bankruptcy-protection petition in Rio last October after its first oil wells produced less than expected and investors lost confidence in the company's ability to keep up with debt payments and finance new oil-field development.
The bankruptcy marked the nadir of Batista's EBX energy, mining, shipbuilding and port-operation group. OGX, the group's flagship company, has lost more than 99 percent of its value since 2010.
The prosecutor's office said Batista knew in advance that those wells were not worth the price of the stock.
Changes to Batista's put option were part of an updated restructuring plan of Oleo e Gas, as OGX is now called, released in May. A final decision on the put option will be based on reports from independent legal advisers, according to the document released by Oleo e Gas.
The prosecutor's office asked for the freeze of Batista's planes, boats, cars and other financial assets in Brazil to later compensate investors hurt by his alleged market manipulations. It also said it will freeze assets Batista transferred to his sons Thor and Olin and his wife Flavia Sampaio.
The dramatic fall of one of Brazil's richest man could have also helped weigh down on confidence in Brazil's capital markets at a time of sluggish growth, business executives have said.
Back in May, a Brazilian court ordered up to 122 million reais in assets held by Eike Batista be frozen as part of an investigation into unfair market practices.