15.6 Your firm has been external auditor of Elgol ple for some years. Elgol has an internal audit department, engaged in both compliance and operational auditing. You have a good opinion of the quality of internal audit work and have established a good relationship with John MacLean, the head of internal audit. He has asked you to give a talk to the members of his department during their annual training week. He would like your views on the different roles of external and internal auditors, the type of work that each carry out and their reporting responsibilities