Australian oil slick five miles long: report
Australian Broadcasting Corporation radio, quoting an employee flown off the rig on Friday, said the spill in the Timor Sea was expected to be larger than initially thought.
Operator PTTEP Australasia, a unit of Thailand's PTT Exploration and Production PCL, has said all 69 workers on board were evacuated safely and emergency procedures activated after the leak developed early on Friday.
Aircraft were expected to begin spraying the slick with dispersant on Saturday, the company said.
The spill occurred at the West Atlas mobile offshore drilling unit in the Timor Sea, which is owned by Norway's SeaDrill Ltd.
Australia's National Offshore Petroleum Safety Authority (NOPSA) was investigating the incident.