The Australian Taxation Office says the "robo-debt" debacle is not its fault and it is unhappy being publicly linked with Centrelink's controversial debt-recovery program.
Senior ATO officials told a Senate committee investigating robodebt on Wednesday that the ATO simply handed its data on taxpayers over to Centrelink's parent department, Human Services, which then used an automated system to raise debts.
It also emerged in Wednesday's hearings that Centrelink had been paid just $24 million of the $300 million it says it is owed under the program with some debtors paying back as little as $5 per week.
But Department of Human Services Secretary Kathryn Campbell said there were no plans to heed the widespread calls for the program to be scrapped and that it would continue with "refinements".
Ms Campbell said the biggest challenges faced by the debt recovery program was a "failure to engage" by Centrelink clients and changes would include using registered mail, simpler language and a better online log-in system.
"The view of the department is that there are a number of refinements that needed to be made, those refinements are being made, and that the system should continue," Ms Campbell said.
Deputy Commissioner of Taxation Greg Williams told senators that his agency "reached out" to Human Services as the public and political backlash against the program grew, only to be told that its help was not needed.
He said it was not technically correct to say the ATO had been involved in "data-matching."