SYDNEY (AFP) - Australia launched an inquiry on Thursday into a major oil spill off its coast which has been described as one of the country's worst environmental disasters.

Retired senior civil servant David Borthwick was appointed to probe the leak, which gushed from a damaged oil well in the Timor Sea for some 10 weeks and then burst into flames before finally being contained on Tuesday.

"I simply say that we aspire to learn from this incident and take any necessary steps to stop similar incidents occurring in the future," Resources Minister Martin Ferguson said.

The inquiry will have the power to call witnesses, take sworn evidence and force companies to hand over documents, and will make recommendations aimed at stopping future accidents.

The rig's Thai-based operator, PTTEP Australasia, has warned the site off northern Australia may need environmental monitoring for up to seven years.

Up to 28,000 barrels of oil poured into the sea after the West Atlas rig began leaking on August 21, prompting several attempts to cap it by boring a relief well and pumping in heavy mud.

Environmental groups have criticised the government's handling of the spill, saying it threatened bird and marine life off Western Australia's north coast.

Resource-rich Australia is enjoying strong energy exports, notably its fast-expanding liquefied natural gas sector fuelled by booming Asian demand.