Centrelink's controversial robo-debt program is under international scrutiny for potential breaches of human rights.

In a submission to the UN's independent expert on poverty, the Human Rights Law Centre has warned the use of automated penalties risks sending families deeper into poverty.

"Computers making decisions about peoples' livelihoods can be the difference between a child having food or going hungry," lawyer Monique Hurley says.

"Single mothers with pre-school aged children have been left stranded and have had to turn to charities for food vouchers.

"The robo-debt debacle has seen the government bully people into paying debts they do not owe, in an attempt to prioritise efficiency over human rights."

However, Department of Human Services general manager Hank Jongen says there is support available if people call the department in distress when they are experiencing hardship and need immediate help.

"People don't have to do this alone. They can call us on the number in their letter and speak to a trained staff member who can help them through the review process," Mr Jongen told AAP.

The HRLC says the human rights impact of technological developments must be prioritised ahead of efficiency and cost gains.

The submission will be used in a report to be presented in October to the UN General Assembly on the human rights impacts of digital technologies in social security systems.

The robo-debt system is a computer program that gathers data from government agencies to see if there are discrepancies with what people have reported to Centrelink.

A third of the appeals to a federal tribunal over the scheme have resulted in debts being set aside, with thousands of welfare recipients who don't owe money sent automated recovery notices.

Before the system was automated 20,000 notices were sent each year, whereas now 20,000 are sent in a week, the HRLC says.

"For such technologies to do good, ending inequality must be central to their design," Ms Hurley said.

The robo-debt program is currently facing two legal challenges, with a Victorian nurse taking Centrelink to court for its claim she owed $2754 for Austudy she was paid while studying a diploma in 2012.

Mr Jongen said the commonwealth ombudsman had reviewed the online compliance system and found it to be comprehensive and in line with the law.

As well, the ombudsman had found it is entirely reasonable and appropriate to ask people to explain differences in data, he said.