The Office of the Australian Information Commissioner (OAIC) has kicked off its audit of the Department of Human Services' controversial Centrelink automated debt recovery scheme.

The OAIC revealed in a legal and constitutional affairs senate committee hearing on Friday morning that it had recently sent a letter to DHS outlining its assessment program, the first step in the process.

The first assessment would begin "shortly", deputy commissioner Angelene Falk said.

Falk said the OAIC had decided to wait until DHS had implemented the recommendations from a damning Commonwealth Ombudsman's report, and then conduct an assessment of the implementation.

The ombudsman said DHS needed to undertake a comprehensive evaluation of the system.

It also recommended that messaging to customers be made clearer, more help be provided to those trying to gather historical information about their income, more assistance be provided to vulnerable individuals, and that automated debts be manually reviewed.

DHS agreed to adopt all the ombudman's recommendations. The so-called 'robo-debt' data matching and debt notice program later received a even more damning report from a senate committee that recommended the program be immediately halted, but the government rejected that report.

The OAIC's assessment is likely to take around six months to complete. Falk said normal practice was that the assessment report would be made public on the OAIC website.

Its review comes as DHS works to expand the program to capture more types of income, however it will do so without the automated debt clarification letters that are behind much of the criticism of the system.

The online compliance intervention (OCI) system matches earnings reported to Centrelink against employer-reported income data held by the Australian Taxation Office (ATO).

A system flags any discrepancies and sends an automated 'please explain' notice to individuals, who are required to explain the gap.

The system has been critiised for comparing averaged fortnightly payments to yearly payments, and for putting the onus on individuals to prove sometimes many years' old employment statuses.

The CSIRO's Data61 unit this week revealed it had signed three contracts with DHS this year to help it fix the scheme.