The spill, in the Timor Sea off Western Australia's northern coast, occurred as a result of a leak from a West Atlas mobile offshore drilling unit on Friday.

Dispersants have been sprayed on the crude oil but the leak could take up to eight weeks to be stopped. Already, oil is covering an area estimated to be 14 kilometres long and 30 metres wide.

Brown said the investigation into the cause of the accident and potential solutions to ensure future spills were prevented required the "full force" of a judicial enquiry.

"Already there are fears that the chemical dispersants being used could have their own toxic effect on the area," he said.

"A judicial inquiry would get to the bottom of any concerns with how the oil rig was being operated and how the early stages of the clean-up were undertaken."

Brown also claimed that Federal Minister for Resources and Energy Martin Ferguson was playing down the seriousness of the situation and called on the Prime Minister to intervene.

Ferguson told World News Australia that the company in charge of the drilling unit, PTTEP Australasia, had minimised environmental damage and brought in experts to determine how to bring the spill under control.