18. Revision by the Commissioner of orders prejudicial to revenue.

(1) The commissioner or any other officer specially empowered by him in this behalf may call for and examine the record of any proceeding under this Act, and if he considers that any order passed therein by any assessing authority or appellate authority is erroneous in so far as it is prejudicial to the interests of the revenue, he may, after giving the assessee an opportunity of being heard and after making or causing to be made such inquiry as he deems necessary, pass such order thereon as the circumstances of the case justify, including an order enhancing or modifying the assessment, or cancelling the assessment and directing a fresh assessment.

(2) The power under sub-section (1) shall be exercisable only within a period of four years from the date of the order sought to be revised was passed.