The Queensland government’s resources investment commissioner has said Adani will have to “Go back to the drawing board” to satisfy outstanding environmental conditions, and that the approval process could take up to two years.

Queensland government officials have been increasingly cautious when speaking publicly about the controversial Adani mine, and none have previously put a timeframe on the approval process.

The Department of Natural Resources, Mines and Energy distance themselves from the commissioner's comments saying “she is not authorised to speak about any specific environmental approvals as the Department of Environment and Science is the appropriate organisation”.