Some serious offenders will be able to cast their votes in the current elections, despite legislation banning prisoners from voting.
The loophole has been revealed in documents obtained from the Corrections Department by a lawyer under the Official Information Act.
Before 2010, prisoners serving a sentence of three years or more were unable to vote. Legislation introduced three years ago put a stop to all sentenced prisoners taking part in elections.
However, lawyer Graeme Edgeler says a small number of prisoners on parole at the time the legislation passed, who were later recalled to prison, are still allowed to vote because they were not covered by the law.
Corrections Minister Anne Tolley says she will ask the department to look into the matter.