The human services minister says he has personally reviewed more than 50 Centrelink debt recovery cases mentioned in the media since Christmas.
Alan Tudge says a third of the cases brought to light have nothing to do with the welfare agency's complaint-prone online compliance system.
In the majority of the cases raised, people still owed money after going through an appeal process, he told ABC radio.
Mr Tudge promised to review two fresh cases brought to his attention and accepted there was a broad problem with Centrelink's debt recovery system.
But he said there were also thousands of people who deliberately chose not to update their incomes when applying for benefits, or inadvertently provided the wrong income information.
If someone is known to be vulnerable and this is reflected on their file, they won't receive Centrelink debt notices, Mr Tudge said.