A Brazilian court froze some $55 million in assets of troubledBrazilian tycoon Eike Batista, as part of an investigation into insider trading, hislawyers said Friday.Once Brazil's richest man, Batista made a huge fortune in oil and gas exploration,but has lost much of it as his EBX Group companies' shares plunged in 2013 and 2014.The investigation began with a report from the securities commission that "pointedthe finger at the practice of 'insider trading,'" his lawyers said in a statement.On the basis of that report, federal prosecutors asked the courts to block 122million reais ($55 million) in Batista's assets in several banks.The securities commission also alleged other infractions, including failure to informthe markets appropriately that reserves owned by Batista's Oleo and Gas Participacoes SA -- an oil and gas group formerly known as OGX -- were smaller thanexpected."Mr Batista denies once again the practice of any wrongdoing and will appeal," hislawyers said.The decline of EBX started in mid-2012, when OGX announced its oil productionwould be barely 25 percent of what had been expected.