Centrelink staff have been instructed to pursue debts they know are incorrect under the Turnbull government’s controversial debt clawback system, a whistleblower claims.

On Thursday, left-leaning activist group Get Up! released an anonymous letter from a Centrelink compliance officer who made five key allegations about the debt-recovery process.

The whistleblower said staff were directed not to fix errors around debts they were chasing, even if they had evidence.

Staff who did had their work rejected and incorrect debts would only be corrected if they were identified by the customer, they said.

The staff member also said incorrect debts were being generated by the inclusion of non-assessable income, by considering payments never actually made by Centrelink, or through a fault that doubled income from the same employer.

A 10 per cent recovery fee, added to the debt owed by some customers, was also being incorrectly applied, they said.

“I see these reviews everyday and I am horrified at what I am being directed to do,” the whistleblower wrote.

“I am risking my job sending this information in the desperate hope that exposing such a corrupt and unjust system might just make a difference.

“Based on what I have seen every single customer should appeal their overpayment, not just reassess online but go through the full appeal process all the way to the tribunal. Please help.”

Staff have reportedly been threatened with disciplinary action or criminal prosecution over internal leaks.

Centrelink denials

Department of Human Services general manager Hank Jongen denied the five allegations, saying the system was working as intended.

Human Services Minister Alan Tudge has been under pressure over the Centrelink controversy. Photo: AAP

In relation to the claim customers’ income was being doubled, Mr Jongen said letter recipients had the “opportunity to review, confirm or change these details in the online system”.

“Some of our staff believe that intensive one-on-one management of recipients is always required,” he said in a statement.

“As with other online initiatives in Centrelink, this intensive support is still available for those recipients who need it and complex cases.

“Many recipients prefer to manage through an online system, in their own time, rather than dealing with a staff member.

“Also, some staff do not welcome technology-driven change.”

The latest allegations come after the Turnbull government made a series of changes to the debt recovery system following weeks of politically damaging criticism.

The government has defended Centrelink’s new tool to recoup debt from those on welfare. Photo: AAP

Independent Tasmanian MP Andrew Wilkie also wrote to the Commonwealth Ombudsman claiming staff had told him they were given a daily debt quota.

These claims were also denied by the department.

Labor has called for a halt to the program and is pushing for it to be examined by a Senate inquiry.

GetUp! has also revealed it is investigating the possibility of an injunction or class action and has launched an automated tool to appeal incorrect debt notices.

When asked by The New Daily how it had verified the anonymous claims, GetUp! Campaigns Director Mark Connelly said a former Centrelink employee had reviewed the letter.

“They agree that it’s clear the letter was written by someone working at Centrelink with knowledge of the operation of the automated debt system and related review processes,” he said.

Labor’s Human Services spokeswoman Linda Burney wants a halt to the program. Photo: AAP

He said the group did not have “the resources to confirm every claim in the letter” but hoped more sources would come forward after its release.

“The claims in the letter are serious and speak to systematic fraud,” Mr Connelly said.

He said the group would target the Western Australian seat of Social Services Minister Christian Porter over the Centrelink controversy.

The Community and Public Sector Union’s deputy national president Lisa Newman said the union’s members had been “able to validate a number of the points” made in the letter.

Australian Council of Social Service chief executive Cassandra Goldie said the new allegations were “disturbing”. She described the debt clawback program as an “aggressive abuse of government power”.

Since July 2016, more than 232,000 letters have been sent to Centrelink customers under its debt recovery program.

New figures released in the mid-year budget update papers show the government expects to regain an extra $2.2 billion from parents, pensioners and people on disability support, Fairfax Media reports.