(1) Nothing in this Chapter shall derogate from the power of the Income-tax Authority to disregard any return, statement or document furnished by a assessee, or the said claim in the course  of audit or assessment proceedings, if it is not verifiable.

(2) Where no conventional method of accounting has been employed, orthe  Deputy Commissioner of Taxes is not satisfied as to the correctness or completeness of the accounts of the assessee, or the accounts of the assessee have not been prepared and maintained in accordance with the provisions of section 73, the assessee shall be assessed in such manner as the Deputy Commissioner of Taxes may think fit.