An attempt to plug an oil leak in the Timor Sea off the north-west coast of Australia, has been unsuccessful.
The ABC reports oil has been leaking from the West Atlas oil rig for more than six weeks.
Operator PTTEP Australasia has been drilling a relief well for the past three weeks.
A statement issued by the company says it reached the target depth of 2.6km below the sea bed on Monday.
However, it has since failed to plug the hole, which is the size of a plate, with heavy mud.
The company said it could take up to four days before it can make a second attempt.