The minister responsible for Centrelink has doubled down in defence of its debt recovery system.

The minister responsible for Centrelink has doubled down in defence of the welfare agency's highly controversial automated debt recovery system.

Alan Tudge flatly rejected the claims of welfare and union groups who argued the "aggressive, fear-inducing" debt program was intimidating clients and placing Centrelink staff in a morally compromised position.

"These statements are being made by people like the unions and ACOSS who frankly have a philosophical objection to doing widespread compliance checks," the human services minister told ABC Radio on Thursday.

"We think this is a critical part of our overall system to ensure there is integrity in the welfare payments."

Mr Tudge denied Centrelink's approach to recovering debts was heavy-handed, despite it launching vastly more interventions since shifting to an automated system in 2016.

He said the welfare agency had conducted income "data-matching" for decades.

"We are doing more compliance checks because we want to be more thorough," he said.

"In the process, we are uncovering egregious examples and we are recouping money for the taxpayer."

About 6600 people first learned they were being targeted via debt collectors, after somehow missing initial correspondence.

The minister blamed these people for failing to update addresses on their Centrelink files.

Centrelink has tinkered with its postal systems, improved its online user interface and established a dedicated phone number to calm concerns of those confused and struggling to navigate the system.

"We're making a bunch of these small refinements and we will continue to do so," Mr Tudge said.

The minister has been referred to the federal police over whether laws were broken in the welfare agency releasing an individual's personal details to the media.

Mr Tudge argues the information provided to the media was approved by his department's chief lawyer to correct false assertions from the individual involved.

"When that occurs it undermines the system overall and we have the power under the act to correct the record."

More than 133,000 debts were raised in the second half of last year under the program, but only eight per cent of the amount owed has so far been retrieved.

The federal government has so far pocketed just $24 million of the $300 million worth of overpayments through Centrelink's automated debt recovery system.

"The number is so small, $24 million, because we have very generous repayment plans, sometimes as little as $5 a week to people who are still on Centrelink payments," Mr Tudge said