The police say fears that the anti-smacking law would lead to good parents being criminalised have proved groundless.
Controversial legislation that changed Section 59 of the Crimes Act was introduced in 2007 and regular reviews have taken place to examine its impact.
The final six-month review showed there were no prosecutions under the law between December 2011 and June 2012. There have been just eight prosecutions since the law's introduction in 2007.
Assistant Police Commissioner Malcolm Burgess said there were 12 reported smacking incidents in the six-month period, with nine people being warned and three resulting in no action.
He said there has been an increase in the number of reports of violence against children since the law came in.
The police attended 355 reports of assaults in children in the six months to June 2012, almost all of which were for more serious crimes than smacking.