Notwithstanding anything contained in this Act, where an objection has been raised by the Comptroller and Auditor General of India in respect of an assessment or reassessment made or scrutiny of any return filed under this Act, and if the assessing authority is satisfied that such objection is lawful, the assessing authority shall proceed to re-assess the dealer or dealers with respect to whose assessment or re-assessment or scrutiny as the case may be, the objection has been made:

Provided that no order under this section shall be passed without giving the dealer an opportunity of being heard.