A Christchurch man has been found guilty of assaulting his young son in a case being seen as a test of the controversial child discipline law.
Musician James Mason, 50, faced three charges of assault of a child under the age of 14 in Christchurch District Court.
The jury deliberated from about midday on Tuesday and returned its verdicts at 9.30pm.
It found Mason guilty on one count relating to a charge that in 2007 he punched his four-year-old son in the face and pulled his ear after he saw the boy and his younger brother riding their bikes dangerously.
Mason was found not guilty on two charges relating to allegations that he picked up bikes the four-year-old and his two-year-old brother were riding and slammed them down.
Mason was remanded on bail until 17 June for a pre-sentence report.
Earlier, Crown prosecutor Deirdre Elsmore told the jury Mason was not on trial because of a law change, but because he was seen assaulting a child.
Crown witness Belinda Payne on Monday told the court she heard Mason shouting at his children and saw him punch his older son in the face.
Defence lawyer Elizabeth Bulger told the jury in her final statement that Mason had been angry and upset, but reminded them there was no injury to the children.
The defence said Mason did not punch his son, but rather pulled his son's hair and flicked his ear, using reasonable force, to prevent the child hurting himself.
Child discipline law
When Section 59 of the Crimes Act was amended two years ago it made clear the use of force by a parent or guardian for the purpose of correction was not justified, but allowed a defence of reasonable force used in order to prevent harm to a child.
Police have said the case would have been brought to court regardless of whether the legislation existed or not.
Former Children's Commissioner Ian Hassall says the conviction may be the best way of dealing with the issue for the family, as the judge has signalled he may give an anger management sentence.
Dr Hassall told Morning Report such a sentence could be appropriate and would provide James Mason with some help.
However, the Law Society says there is no evidence that the child discipline law has reduced instances of violence against children.
Chairperson of the family law section, Paul Maskell, says he has seen no let-up in people suffering family violence or asking for protection orders.
Mr Maskell says he has greater support for new moves to give police the ability to issue on-the-spot protection orders.