People pursued by Centrelink over its controversial "robo-debts" are being denied the protection of Australian consumer law, a Parliamentary inquiry has been told.

The welfare agency is exempt from laws and guidelines covering debt collection by private businesses, "even the much maligned banks", according to the chief executive of Victorian community organisation Family Care, David Tennant.

But Centrelink says that it, and the private sector debt collectors hired to pursue its clients, are compliant with legal requirements.

Mr Tennant, who has a background in consumer law, says much of Centrelink's activities in pursuing its millions of dollars in "robo-debt" would be illegal if done by a non-government player.