The Comptroller & Auditor General of India (C & AG) is the supreme head of the Indian Audit & Accounts Department and is the final authority of audit in India.
The Office of the Principal Director of Audit, Railway Production Units & Metro Railway is a subordinate office under the Comptroller & Auditor General of India with headquarters at Kolkata.
The Principal Director of Audit is responsible for a detailed test audit of the accounts of CLW, BLW and Metro Railway, Kolkata in the manner and to the extent as laid down in the Railway Audit Manual and the Secret Memorandum of instruction regarding the extent of audit and in accordance with the orders issued from time to time by the Additional Deputy Comptroller & Auditor General of India (Railways).
The Principal Director of Audit is responsible to the Additional Deputy Comptroller & Auditor General of India (Railways) for the audit of all receipts and expenditure of the various units under his control. As regards the administrative function of the office he is directly responsible to the Comptroller & Auditor General of India.
The powers of the Principal Director of Audit, relating to technical matters are derived from the C & AG's Manual of Standing Orders (Audit) and relating to the scope and extent of audit are detailed in the Secret Memorandum of Instructions (Railway Audit). He has been authorised to exercise all powers as "Head of the Department" under the "Fundamental Rules & Supplementary Rules".