Assessee-firm filed its return for relevant assessment year declaring total income as nil. Assessment was  reopened assessment based on information from Investigation Wing that assessee maintained a bank account with ING Vysya Bank with substantial amount of credit entry which was not disclosed by assessee in its return. The  Assessing Officer disallowed deduction under section 10AA.  Principal Commissioner invoked revisionary jurisdiction on ground that Assessing Officer had not made any inquiry in respect of credit entries and same remained undisclosed and  held that assessment order passed by Assessing Officer was erroneous and prejudicial to interest of revenue.  Tribunal held  that Assessing Officer had examined two issues raised in reopening of assessment under section 147 viz. credit entry in bank account and disallowance of deduction under section 10AA and  set aside revisionary order on ground that entries in said bank statement were examined by Assessing Officer in reassessment proceedings. High Court held that Assessing Officer had conducted sufficient inquiry and it was not a case of ‘no inquiry’ or ‘lack of inquiry’, thus, when an opinion was formed as a result of inquiries, which was in exclusive domain of Assessing Officer, it was not open for revisional authority to arrive at conclusions merely on basis of a subjective exercise It was  not case of failure to investigate, but one where no addition was made on issue. SLP filed by revenue was dismissed.  against impugned order of High Court was to be dismissed.  (AY. 2012-13)