Regulators are investigating Indian mining giant Adani over conflicting claims it's cheating the migration system and seeking permanent residency for foreign workers.
Reports by The Australian claim an internal company review by Ernst & Young found none of Adani's foreign workers were properly registered or accredited to work as engineers in Queensland.
It also claimed most foreign workers had been wrongly imported on short-stay 456 visas, which allow people to visit for meetings but ban most types of work.
According to The Australian concerns have also been raised about pay differences between foreign and local workers.
Adani is driving the $10 billion Carmichael coal project in the Galilee Basin, and it expects to employ 5,000 people during construction with a permanent workforce of 4,000.
AAP reports Adani has denied it is also seeking an enterprise migration agreement, similar to the one in place at Gina Rinehart's Roy Hill project, to import much larger volumes of overseas talent.
According to AAP Adani has roughly 50 foreign workers in Australia and the company says it's maintaining full compliance with migration law.