A peace activist has won an appeal in the Supreme Court against a conviction for offensive behaviour after setting fire to the New Zealand flag during an Anzac Day service in 2007.
Valerie Morse was convicted in the District Court of behaving in an offensive manner in a public place and fined $500.
The Wellington woman was protesting against New Zealand's involvement in the war in Afghanistan when she burned a flag during a dawn service.
The incident occurred in the grounds of the Law School in Wellington. Others in the protest group sounded horns as a former Secretary of Defence started to speak at the service.
The District Court judge interpreted offensive behaviour under the Summary Offences Act to mean behaviour capable of wounding feelings or arousing real anger.
The decision was later upheld in the High Court and the Court of Appeal.
But the Supreme Court on Friday ruled that offensive behaviour must give rise to a disturbance of public order.
All five Supreme Court judges ruled that the District Court trial was not guided by correct legal principles. They quashed the conviction, saying the case does not need to be reheard.
Ms Morse argued in the Supreme Court that she had the right to freedom of expression to make a political protest under the Bill of Rights and wanted to set a legal precedent.
She says despite the cost of her fight, she has no regrets.
The Supreme Court decision may make it more difficult for police to prosecute people who burn the New Zealand flag.
Auckland University law professor Bill Hodge says the decision will raise the bar for police prosecution of those who are committing offensive acts.
Returned and Services' Association chief executive Stephen Clarke says the decision will upset some veterans.