Bureaucrats have been accused of cherry picking some "positive perceptions" of income management in the Northern Territory to justify its expansion in other states.
Australian Greens senator Rachel Siewert used a senate estimates hearing to grill officials from the Department of Families, Housing, Community Services and Indigenous Affairs (FaHCSIA) about an independent evaluation of income management in the NT released late last year.
That preliminary report said income management was a disempowering control measure and there was little evidence it was helping people.
Senator Siewert said the report found no measurable evidence of any positive impact from income management or that it was changing behaviour.
In a heated exchange, Senator Siewert asked why, in the light of those findings, the federal government had proceeded with its Stronger Futures legislation (which continues the NT intervention for 10 years) without addressing problems with income management.
Department secretary Finn Pratt said the preliminary report had "mixed findings".
"There is much in the report that points to positive signs as to negative ones," Mr Pratt said.
Department official Liz Hefren-Webb said it was based on interviews of about 800 people and some had said income management had improved their lives.
"We consider that pretty valid evidence about how they feel about the program," she told the hearing.
Senator Siewert said that in five-and-a-half years the department had not measured the success of the program other than some positive perceptions from participants.
"How much more time do they need?" Senator Siewert told AAP.
"How can the expansion of income management continue without a strong evidence base, and in the face of the growing costs and community opposition to the regime."
The hearing was told administration costs of income management were between $6600-$7900 per person per year in the NT.
Mr Pratt said that would drop if more people were put on income management.
Asked if there were plans afoot to further expand income management, he said that was a government decision.