Social Services Minister Christian Porter has defended the Federal Government's new debt recovery system by Centrelink following claims some people have been mistakenly targeted.

Labor has cited incorrect findings in calling on the Government to suspend the system, which cross references employment data from the Australian Tax Office and Centrelink.

But Mr Porter said the system was working, citing a low complaint rate in response to the 169,000 letters sent out since July.

He told the ABC that the majority of people contacted have not been required to provide any supporting documentation, instead asked to go online and update information.

"These are not debt letters," he said.

"They are polite letters, the initial letter that goes to the welfare recipient saying that an issue has arisen, that there may be a discrepancy and we require some further information."

Automated system gets 'enormous number of complaints'

Some recipients are required to supply paperwork from up to five years ago, but Mr Porter said that applied to a "very small number" of people.

He added that the system had recovered $300 million since the start of the financial year.

"What this system is doing is raising real debts around real overpayments based on real cross referencing of evidence," he said.

But Shadow Minister for Human Services Linda Burney said it should be suspended, citing "inherent problems right across the system".

Ms Burney told the ABC on Monday that she had written to the Minister over the matter, citing an "enormous number of complaints".

"It's an automated system that has clearly got enormous problems," she said.

"Why should it be the recipients' responsibility to prove they're right when the Government is making the mistake?"

Ms Burney today tweeted that the system needed to "get it right before threatening people", referencing the #notmydebt social media campaign launched in response to Centrelink.

Last week, Liberal backbencher Eric Abetz said the system should be "ironed out" if there were issues with false findings, but did not go so far to call for its suspension.

"If people have been over-claiming, then indeed they should be paying back," he said.

"If there is a fault in the system in relation to the request for repayment, then in those circumstances, of course the situation ought to be revisited."

Late last month, the man in charge of the new system said that those feeling "lost in the system" should write to him directly.

Hank Jongen, the general manager of the Department of Human Services which runs Centrelink, told Triple J's Hack program that the system was not designed to accuse people of rorting.