Site restoration fund deduction limits taxable business profits when prescribed deposits, audit and usage conditions are met. An assessee engaged in petroleum or natural gas operations who deposits amounts (including credited interest) into a specified account-either a special account with the State Bank of India under an approved special scheme or a site restoration account under a deposit scheme-and obtains the prescribed audit report may deduct the lesser of such deposits or twenty percent of business profits before this deduction. Withdrawals are limited to scheme purposes; unauthorised withdrawals, unutilised releases, or certain asset disposals produce deemed business income and expenditure met from the account is not separately deductible.