Due diligence obligations require lead merchant bankers to ensure disclosure accuracy and maintain responsibility until securities delivery and listing permission. Regulation 64 requires lead merchant bankers to exercise due diligence regarding all aspects of an issue, including disclosure veracity and adequacy, and to require issuers, promoters, directors or selling shareholders to fulfil disclosed and regulatory obligations. Post-issue merchant bankers remain responsible until securities are delivered or refunded and listing agreements and listing/trading permission are secured; lead merchant banker responsibility continues after issue completion.