Singtel-owned Optus brought in Kerry Schott, an executive with roles in the business and government sectors, to lead an independent review into the cause of a disruption to its emergency call system last week which led to multiple deaths.

In a statement, Optus chair John Arthur noted Schott’s extensive cross-industry experience at the executive and board level in the public and private sectors, “ideally equips her to undertake this review”.

He added the board is working with CEO Stephen Rue and his team to develop a “full understanding of what went wrong and why, and what we need to do to prevent any repetition”.

“What has occurred is clearly unacceptable and on behalf of the board I apologise for this failure in our accountability to all those who relied on our Triple Zero services.”

The review is expected to be completed by the end of the year, with Schott to first report the findings to the operator’s board before making them public.

It will examine the operational management of emergency calls, covering the monitoring and operational effectiveness in relation to the incident.

The 13-hour outage is the second major disruption to the Australian operator’s network in less than two years.