Section 112 of the prohibited the exportation of mineral sands unless authorised by the Minister. Murphyores Inc Pty Ltd, which held leases from the state of Queensland to mine mineral sands on Fraser Island, sought permission from the Minister to export mineral sands. Such authorisation was withheld pending the outcome of an environmental inquiry. Murphyores challenged the constitutional validity of prohibition and sought an injunction to the study, and a declaration that the Minister cannot make a prohibition for environmental purposes.
In a unanimous decision, the court held the legislation was a valid exercise of the trade and commerce power. Section 51 was a non-purposive power, and the only relevant factor was the subject matter of trade and commerce. The motive and purpose behind the legislation was irrelevant.