Australia has rejected the jurisdiction of an international tribunal on which East Timor is relying to deliver a greater slice of oil and gas revenue.

East Timor remains incensed by claims Australia spied during negotiations for a Howard-era treaty to share oil and gas deposits in the Timor Sea.

The tiny nation has invoked a never-before used "conciliation commission" under the international law of the sea in a bid to end a bitter impasse over drawing a maritime boundary.

Former prime minister and independence hero Xanana Gusmao told the opening hearing of the commission on Monday that East Timor was not asking for favours or special treatment, just its rights under international law.