Your firm was recently appointed as the auditor of Eccah Sdn Bhd, a company manufacturing and supplying engines to the car industry. The company manufactures made-to-order car engines for its regular customers and has good relationships with its local suppliers. The company has a December year-end and uses a computerized accounting system. You have been assigned to review the audit working papers of the company. Extract from the company's financial statements as at 31 December 2016: Trade payables 9,350,000 12,345,000 Information of the trade payables has been highlighted for your attention during file review: (a) Raw materials are purchased from local suppliers, most of whom are paid via cheques within three months. (b) Some suppliers require a contract to be drawn between the company and the suppliers that specifies the terms and references of credit given to the company. (c) The inventory count was conducted on 31 December, during which it was noted that the last good received notes number was XYZ123. (d) A listing of all the trade payables at both the current and previous year-ends was included in the audit working papers. (e) A listing of all the trade receivables was not included in the audit working papers. (1) The credit department comprises three staff-the credit manager and two other staff members. Required: Describe the substantive audit procedures that you should expect to find during your review of the working papers to verify the trade accounts payable balance at year-end and that the amount is not understated.