Purpose - The paper examines the impact of involvement in Enterprise Risk Management (ERM) on internal auditors' willingness to report a breakdown in risk procedures and whether a strong relationship with the audit committee affects willingness to report. The study also investigates the use of ERM and the role of internal audit in ERM. Design/methodology/approach - The study uses an experimental design, manipulating (i) the internal auditor's involvement in ERM and (ii) the strength of the relationship between internal audit and the audit committee. Participants are 117 certified internal auditors. The study also gathers descriptive data on the use of ERM. Findings - The study indicates that a high involvement in ERM impacts internal auditors' willingness to report a breakdown in risk procedures to the audit committee. However, a strong relationship with the audit committee does not appear to affect willingness to report. The study also finds that the majority of organisations have recently adopted ERM. Internal auditors are involved in ERM assurance activities but some also engage in activities that could compromise objectivity. Research limitations - There are internal and external validity threats associated with the experimental design. Practical implications - The findings reinforce the need for organisations to adhere to the recommendations of the IIA and to ensure that internal auditors do not play an inappropriate role in ERM. Originality/value - The study contributes to our understanding of the impact of involvement in ERM on internal audit objectivity and of the current role of internal audit in ERM in Australia.