Australia has sent 554 New Zealand citizens home since tightening up its immigration policy on people with criminal records - and many have re-offended.

An Official Information Act request by the Otago Daily Times has revealed 122 of them have already been arrested, and charged with criminal offences.

Most of the 422 charges they face involve dishonesty and traffic crime.

However, there are also nine sex charges and 81 prosecutions involving violence.

The changes came into force a year ago, beginning a systematic deportation of foreigners who don't meet a good character test.

Kelvin Davis, Labour's Corrections spokesperson, believes that some re-offending was inevitable given that the returnees weren't given adequate support "so that these people don't resort to a life of crime."

"They're coming back with no job, no shelter, no food, no clothes, and no family, and no support structures whatsoever," Davis said. "The government is not doing their bit to keep New Zealanders safe."

Davis said organisations which support prisoners are severely under-resourced and struggling to support the level of need.