Assessment inquiry powers: Officer may require returns, documents or nominated audits, subject to approvals and procedural safeguards. Section 142 authorises the Assessing Officer to require returns, production of accounts or documents, and written verified information including assets and liabilities; prior approval of the Joint Commissioner is required before demanding statements of unaccounted assets and accounts older than three years cannot be compelled. The Officer may, with prior approval of senior Commissioners, direct audit by a nominated accountant or inventory valuation by a nominated cost accountant and require prescribed reports within specified periods subject to limited extensions. Expenses for such audits are determined by senior Commissioners and generally payable by the assessee, and material obtained must be afforded an opportunity of being heard before use in assessment.