New Zealand’s worst rapist, Ronald Van der Plaat, will soon be released from prison despite being categorised as a medium-high risk of committing further offense. The man kept his own daughter, Tanjas Darke, for 23 years as his sex slave and hung her to the ceiling, with her head locked in a box while performing the sexual act.

The 82-year-old Van der Plaat was imprisoned for 15 years since 2001 for his offense. However, he will be walking free once he completed his jail term despite the opinion of the New Zealand Parole Board that he poses an undue risk to the safety of the community given his consistent denial of his sexual deviation and failure to seek rehabilitation, New Zealand Herald reported.

Van der Plaat was denied of an early parole yet he will be freed on May 11. In the documents submitted by the parole board, it showed the evaluation made by the psychologist that indicated Mr. Van der Plaat’s possible decline of cognition, progressive aging and lack of insight about his risk.

The evaluation also signified that his continued denial of his sexual deviancy, along with the collusive social supports, hampers relapse prevention planning. The psychologist concluded that his increasing physical fragility within the external controls may potentially reduce his sexual recidivism risk over time.

The abuse made to Darke began when she was 9 years old and was continued on until the daughter’s 30s. She was able to write a book regarding her ordeal, titled “Flight of the Dancing Bird.”

New Zealand’s worst rapist is going to be prohibited from communicating with his daughter unless he gets a written permission from the probation officer. He will not be allowed as well to bring around any device that is capable of recording videos or taking pictures, and will be prevented from going into a school, park, beach, kindergarten, library or a child care center, Daily Mail reported.