About 30 percent of New Zealanders deported from Australia because of their criminal convictions have gone on to reoffend in this country.
The figures are in briefing papers to incoming Police Minister Judith Collins.
The documents said the deportee offending which had come to the attention of police since law changes in December 2014 included sexual and violent offending.
Police expected rates to be as high as 55 percent after two years.
The governments of both countries are trialing an information-sharing arrangement aimed at reducing the risk of returning offenders, the documents said.