Eike Batista, who was Brazil's richest man for most of the past decade, is under investigation for allegedly engaging in insider trading while he chaired his now-bankrupt oil-producing and shipbuilding firms, securities industry watchdog CVM said on Friday. In a statement sent to Reuters, Rio de Janeiro-based CVM confirmed that Batista is a respondent in six of nine probes that executives of his Grupo EBX conglomerate are facing for breaching securities rules. In two of them, regulators are examining whether Batista allegedly took advantage of his access to privileged information.