November 2, 2009 Oil rig and platform catch fire during attempt to plug spill in Timor Sea Play video

(NECN/AuBC/CH7) - Australia's government on Monday promised an investigation after a massive fire erupted on an oil rig that had been leaking into the Timor Sea, the latest drama in a 10-week saga to plug the hole.

Rig operator PTTEP Australasia said no one was injured and non-essential workers were evacuated after the fire broke out on the West Atlas rig and Montara wellhead platform on Sunday.

The blaze started when workers began pumping heavy mud into a leaking well casing.

An estimated 400 barrels of oil a day have escaped from the hole since 21 August.

Officials had planned to pour more mud into the leak on Monday in the hopes of removing the source of fuel from the fire, which was sending massive plumes of smoke into the sky.

But in a statement, the company said it was still in the process of mixing four thousand barrels of heavy mud and would not be ready to pour it down the well until Tuesday.

On Sunday, PTTEP Australasia chief financial officer Jose Martins said the company did not know how the blaze started.

There were, he said, many unanswered questions, but the company's sole focus now was the safety of all personnel, bringing the fire under control and stopping the leak.

"We remain committed and resolved to achieve our goal and that may require a few more attempts over the next 10 days, 10 to12 days," he said.

Federal Resources Minister Martin Ferguson on Monday said that once the

Conservationists, however, have been critical of the response to the spill and have expressed concern for the marine life off the Kimberley Coast.

"We're worried that this fire will add to the toxic cocktail that has already been seen with the oil spill," said John Carey from the PEW Environment group.

Greens leader Bob Brown accused Ferguson of making "a compete botch" of dealing with the spill and said the incident was "one of the biggest environmental catastrophes the Commonwealth government has had to deal with" .

The oil slick from the rig, about 150 miles off Australia's northwest coast, now stretches across thousands of miles (kilometres) of remote ocean.

Indonesia said last week that thousands of dead fish and clumps of oil had been found drifting near its coastline.