The Federal Government is spruiking its welfare crackdown as a success after saving $1.4 billion over 18 months, including one case where a man was jailed for three years for fraud.

The Department of Human Services (DHS) has come under fire for its crackdown, amid the bungled Centrelink robo-debt program which saw large numbers of people wrongly pursued for overpayment of social security benefits.

But Human Services Minister Michael Keenan is not convinced that takes the gloss off the money the Government has been able to save.

"It shows you that we are actually serious about making sure that people only get what they're entitled to," he said.

"There were certainly aspects of that that could've been handled better.

"But the fundamental principle remains the same, and that is people should expect that they can get what they need from the welfare system, but it's not reasonable to overclaim from it."

More than 1,400 examples of possible welfare fraud were investigated by DHS, and more than 900 were referred to the Commonwealth Director of Public Prosecutions.

"We've had examples with someone defrauding the system by $160,000," Mr Keenan said.

"They were found guilty and fraud and sentenced to three years in prison, and that's a very bad example.

"But anybody who's over claiming from the system, anybody who's been getting more than they're entitled can expect that the Coalition Government will go after them."

DHS has been using data matching technology since mid-2016 to detect discrepancies in payments, and the Coalition said that has increased the number of yearly welfare checks by half a million since it has been in office.

A Senate inquiry into Centrelink's handling of the robo-debt saga called on the program to be suspended.