Montara Commission of Inquiry

Date published:
1 October 2017

The leak took place in the Timor Sea, off the northern coast of Western Australia, between 21 August and 3 November 2009. The incident resulted from a wellhead accident on an offshore drilling platform owned by PTT Exploration and Production (PTTEP) Australasia.

The inquiry was established under Part 9.10A of the Offshore Petroleum and Greenhouse Gas Storage Act 2006. It looked into the likely cause of the incident and the effectiveness of regulations.

Implementation report

Following the inquiry, the government implemented 92 accepted recommendations from the inquiry.

The Australian Government Report on the Implementation of the Recommendations from the Montara Commission of Inquiry details these actions.

The implementation report demonstrates the government’s commitment to apply the lessons from the 2009 Montara and 2010 Gulf of Mexico oil spill incidents. It highlights actions by governments, regulators and the offshore oil and gas sector to improve regulatory and operational practices in Australia.

Commission reports

The Montara Commission of Inquiry Report found a number of operational and regulatory failures and contained 105 recommendations.

The Commissioner David Borthwick AO PSM provided the report to the Minister on 17 June 2010. The government released the report and a draft response on 24 November 2010.

Noetic Solutions also conducted an independent review of PTTEP’s response to the spill.

Commission hearings

Hearings for the Montara Commission of Inquiry were held from 15 March to 16 April 2010.

See the documents from the proceedings on the the Australian Government's web archive:


The Commissioner called for submissions to the Inquiry from 5 November to 5 December 2009. Companies involved in the Montara Field Development, the leak response, and other stakeholders provided submissions.