Spill comes less than 18 months after a fire on the same oil rig and prompts warning from environmentalists over dangers of offshore drilling
An oil spill at an ExxonMobil platform in the Bass Strait is being investigated by the federal regulator, after the discovery of an oily sheen on waters around the rig.
The spill comes less than 18 months after a fire raged on the same platform for nine hours before it could be controlled. And in 2013, Exxon was responsible for a spill from another rig in the Bass Strait.
Related: North Sea or Great Australian Bight, oil drilling is always a risky business | John Sauven