It is only the second such prosecution in New Zealand history.
Bill Kerr was president of the Hakaru RSA for six years, having produced a certificate of service on arriving in Mangawhai and wearing five medals to veterans' parades.
The medals he wore included The Vietnam Medal, which was awarded from 1968 onwards to those who served in the controversial war.
But it led to suspicion about Kerr's service because he had served in the Royal New Zealand Navy - and wasn't one of the 15 people from the Navy who had served in Vietnam.
Kerr, in his 70s, was convicted in the North Shore District Court on Thursday of wearing medals to which he was not entitled to wear and fined $250.
Contacted by the New Zealand Herald, he said: "I've got no comment to make."
Northland RSA president Ian McDougall, who joined the Navy in 1964, said he became suspicious while at an event and talking to Kerr about his service background. What he was told didn't ring true, he said.
"I did a bit of research and found out he wasn't the war hero he claimed to be. I'll make sure no other RSA in Northland will touch him."
Kerr's Vietnam medal was the clincher, he said. It had been awarded to a limited number of Navy medics who served in the conflict.
Mr McDougall said there needed to be higher penalties than those set out in the current law, last upgraded in 1974.
He pointed to a private members bill put forward by National Party MP Todd Barclay, which would make the maximum penalty $5000 or a maximum of six months in prison.
"With these guys coming back from Afghanistan, there's bound to be some wannabes who weren't there but want to be recognised as heroes."
The new Hakaru president, Graeme Hitchcock, said Kerr had medals signalling service in Vietnam and two others to which he wasn't entitled.
"It's disgraceful and disrespectful to those who have actually earned their medals. It really degrades those who have done their thing properly. It's shocking."
Sergeant Geoff Medland said the prosecution established Kerr was wearing medals that were not his.
"It's important it's brought to the public's attention. There is a national feeling of disgust around people purporting to be war heroes."
Kerr's conviction follows the pretence of Kaukapakapa's Rob Clark, who turned up at an Anzac Day service wearing a host of medals he never earned, portraying himself as a member of the NZ SAS.
He admitted to the Herald he had only served for a few years in the NZ Army in the early 1990s and was only entitled to one of the 15 medals he was photographed wearing.
Questions about Kerr's service heightened after he quit a neighbourhood society called The Anchorage Association, for which he was treasurer.
In the wake of his exit, his wife Valerie (73) was convicted on three charges of forgery and one charge of presenting a forged document in relation to the association's funds. She was ordered to repay money taken and carry out 50 hours' community service.
Irene Donaldson, who took over as treasurer, was one of those who went through the association's records after concerns about some of the transactions in the accounts.
"The committee took a stand and said, 'You can't do this to friends and neighbours'. We gave him options to put it right but he backed away from that."
Valerie Kerr's conviction led her to the RSA, where her husband arranged for her to carry out her community service. Once a complaint was laid with police over his medals, neither were seen again at the RSA.
Kerr's conviction should dispel concerns the over whether the Military Decorations and Distinctive Badges Act 1918 is fit for purpose.
Sgt Medland said the legislation was "antiquated" but "very clear".
It's a view supported by legislation guru Grame Edgeler, who analysed the legislation for the Herald on Sunday, and said it was clear that those wearing medals to which they weren't entitled faced a fine of up to $500.
Mr Edgeler said "stolen valour" laws in the United States had failed on freedom of speech grounds and the limit had been set when claims of service were used to commit fraud, such as asking for donations.
"In my opinion, the same should apply in New Zealand. Unless you are committing fraud, there does not need to be a law covering the unauthorised wearing of service decorations.
"People shouldn't falsely claim to have served in the military, and people shouldn't falsely claim to have been decorated for valour, but the appropriate response to anyone who does it is public derision."
Todd Barclay said his private members bill, which had yet to be pulled from the ballot, had met some approval from former ministers of defence, Gerry Brownlee and Jonathan Coleman. He had yet to speak to the new minister Mark Mitchell about it.
"At a basic level, it's disrespectful to break the law but in its current state there's no form of reprimand so no disincentive for people not to do it."
