Assessee-company was running a multi-speciality hospital and claimed referral fees as expenditure which was paid to doctors for referring their patients for treatment in assessee’s hospital.  Assessing Officer allowed said claim.  Later, Assessing Officer issued reopening notice after expiry of four years on ground that expenditure claimed as referral fees paid to doctors being an expense prohibited by law was to be disallowed under Explanation 1 to section 37(1) of the Act, Court held that   since claim with respect to referral fees was already considered and allowed during regular assessment proceedings and no new material was brought on record, reopening assessment merely in view of Circular No.5/2-12 dt 1-8-2012  Circular No.and MCI Regulations, 2002 which were available during regular assessment, would be mere change of opinion.  (AY. 2011-12, 2012-13)