The degree of culpability varies among the 700 or so people who made incorrect claims.(ABC Kimberley: Vanessa Mills)
The Australian Tax Office may be forced to reveal details of an outback tax scam that saw large amounts of money wrongly paid out to northern residents.
Last year, word spread quickly through the small bush towns of the Kimberley about an easy way to get free money, by entering incorrect information on tax return forms.
About $20 million was incorrectly claimed before the ATO closed the loophole.
The agency has refused to say how much was paid out, but the ABC understands some people received as much as $80,000 to which they were not entitled.
The ATO has also not disclosed how much money has been recovered nor if anyone is being prosecuted in relation to what it has described as a "fraudulent scheme".
Liberal senator for Western Australia Dean Smith said the public deserved to know more.
"Taxpayers have a right to know exactly what happened, as well as what the ATO is doing to remedy the problem and to protect the community from future schemes," Senator Smith said.
"During the upcoming Senate estimates hearings in October, I will ask the ATO questions about the scale and recovery of the money involved and what is being done to prevent this behaviour in future."
Tax office maintains silence
The ATO has faced a difficult task trying to recover the funds.
Those involved are mainly from Aboriginal communities in the West Kimberley and the towns of Broome and Derby.
Some do not have working mobile phones or mailing addresses, and some have ignored ATO requests to negotiate repayment plans.
The degree of culpability varies among the 700 or so people who made incorrect claims.
People shared on social media pages a description of how to enter inflated numbers in the online tax return forms, and ATO assistant commissioner Karen Foat said last November that some did not realise what they were doing was potentially illegal.