The suit, filed through the company's subsidiary Petrotimor, could amount to more than $US30 billion ($39 billion) and alleges a pattern of corrupt behaviour of ConocoPhillips over the past 30 years with complicity from both Australian and Indonesia.
Petrotimor and Oceanic Exploration claims that the Portuguese rulers of East Timor granted it exploration rights over the Timor Gap before Portugal abandoned the colony in 1974.
However in 1975 Indonesia invaded East Timor and took control, which eventually lead to Australia and Indonesia striking the Timor Gap treaty in 1989.
A new treaty was then negotiated with East Timor following its independence in 2002.
In early 2003 the full bench of the Federal Court in Sydney rejected a $2 billion claim by Petrotimor for the loss of rights to the vast oil and gas reserves in the region ruling that the issue could require interference in Australia's international relations and foreign policy and so the court did not have the power to act.
