The Timor Sea

Australia, Timor and the Timor Sea

The long and contentious history over the maritime boundary between Australia and Timor-Leste is a troubling example of the corruption too often associated with the powerful.

A little history

In 1975, Timor-Leste declared its independence from Portugal, but soon after, Indonesia invaded and annexed the territory.

In 1989, Australia and Indonesia signed the Timor Gap Treaty, which established a joint development zone for oil and gas exploration in the Timor Sea – the Joint Petroleum Development Area (JPDA) with each nation set to receive 50% of the profits. The Timorese people were not consulted in the negotiations and did not benefit from the treaty. The JPDA included the resource-rich fields of Laminaria-Corallina, which by the mid 2020s were all but depleted with Australia and majority-owned Australian resource companies receiving all the profits.

Following a referendum on 30 August 1999, Timor-Leste voted for independence from Indonesia, leading to violence and displacement on a huge scale. Two weeks later an international peacekeeping mission led by Australia entered the territory, marking the beginning of period of stability under the United Nations in preparation for the establishment of independence. On 20 May 2002, Timor-Leste became a sovereign state.

Spying on a new State

On that day the Australian Prime Minister and Foreign Minister signed a re-negotiation of the Timor Sea Treaty with the Timorese leaders ensuring that the Timorese received 90% of the JPDA and Australia 10%. The JPDA lies 100% on the Timorese side of half-way, the median line.

A further area of dispute involved the Greater Sunrise Troubador area adjacent to the JPDA and partially overlapping it. Discussions over the sharing of the resources in this area were governed by an agreement entitled Certain Maritime Arrangements in the Timor Sea (CMATS). In 2004 the Australian government spied on the Timorese negotiators, principally in regard to CMATS. The espionage operation, which was conducted by the Australian Secret Intelligence Service (ASIS), involved bugging the offices of the Timor-Leste government during negotiations.

The spying was designed to gain an advantage in the negotiations and secure a better deal for Australia and its resource companies, such as Woodside and Conoco-Phillips, in the division of oil and gas reserves.


‘Witness K’ – one of the spies – later complained, and as a result suffered challenge to his employment arrangements. He was advised by ASIS to seek legal advice and was allowed to approach Bernard Collaery, who at the time was an adviser to the Timorese government.

Upon realising that they had been spied on, the Timorese withdrew from the Treaty. In December 2013 the domestic intelligence service, the Australian Security Intelligence Organisation (ASIO) entered Collaery’s home-office under warrant and removed documents. Witness K’s premises also were entered and his passport was taken (and is yet to be returned).

In 2014, Timor-Leste initiated legal proceedings against Australia in the International Court of Justice (ICJ) and the Permanent Court of Arbitration (PCA) over the espionage operation. Timor-Leste argued that the operation had breached international law and undermined the legitimacy of the Timor Sea Treaty. The ICJ ordered Australia to stop spying on its neighbour and invoked a Compulsory Conciliation as a means of resolving the issue. Australia is the only nation so far to have been subject to this little-know UN instrument.

In 2017, the two countries reached a confidential settlement in the PCA, under which Australia agreed to withdraw from the maritime boundary dispute and support the development of Timor-Leste’s oil and gas reserves in the Timor Sea. The settlement was seen as a significant victory for Timor-Leste and a step towards repairing relations between the two countries.

A final Treaty

In March 2018, Australia and Timor-Leste reached an historic agreement on the maritime boundary, which established a permanent boundary and a revenue-sharing agreement for the oil and gas reserves in the Timor Sea. The Timor Sea Treaty was replaced by the Maritime Boundaries Treaty. The agreement was seen as a significant victory for Timor-Leste, which will now receive a greater share of the revenue from the resources in the Timor Sea, that is 70% – 80%, depending on the mode of extraction. Australia is set to receive 20% of the resources of this area.

The prosecutions begin

Two months later, in May 2018 the Commonwealth Director of Public Prosecutions recommended to the Attorney-General that both Collaery and K be prosecuted for exposing the espionage. Witness K pleaded guilty in 2021, while the prosecution of Bernard Collaery was dropped under the new Labor government in July 2022.

The Australian government continues to “neither confirm nor deny” that the espionage took place. Both men are under orders not to disclose a variety of associated matters.