A refugee boat carrying an unknown number of asylum seekers was spotted off the north-west Australian coast on Monday, media reports said.
The vessel was first seen by a police boat searching for missing sailors from a downed trawler, Xinhua reported.
The boat, according to local media reports, was spotted just 70 km off the coast.
The vessel is the only the second to breach Australia's maritime borders since the Tony Abbott government introduced a "turn back the boats" policy in 2013.