The Central Bureau of Investigation (CBI) on Wednesday said it has filed a charge sheet against the chairman and directors of two Kolkata-based private companies in a chit fund fraud case of Rs 335 crore.The two companies, Angel Agritech Ltd and Angel Rural Development Ltd, allegedly collected money from the investors under its investment schemes by fraudulently promising very high returns but later closed operations and wound up their business without repaying the promised amount of approximately Rs 335 crore, said a CBI release."CBI has filed a charge sheet against the Angel Agritech Ltd Chairman S.K. Hasibul Haque and Managing Director S.K.Najibulla alongwith the two companies on the charges of criminal breach of trust (IPC 409), criminal conspiracy (IPC 120B) and under various sections of Prize Chits and Money Circulation Scheme (Banning) Act," the release said.The charge sheet has been filed before the Additional Chief Judicial Magistrate of South 24 Pargana's Baruipur.The CBI, that is probing the case since November 2014 on the order of Supreme Court, said further investigation in the case is kept open for determining the larger conspiracy and money trail.