Section 158(2)(a) in The Calcutta Municipal Corporation Act, 1980
(a)expenditure from the revenue of the Corporation, expenditure on account of loan and works, and other expenditure, if any, and shall ascertain whether the moneys shown therein as having been disbursed were legally available for, and applicable to, the services or purposes to which they were applied and whether such expenditure was an expenditure authorised under this Act;