"I think people are so familiar with gangs in New Zealand, I don't think anyone would be silly enough to put a knock-off patch on.
"There's a lot of morons out there, don't get me wrong, but it seems a step too far even for a fool."
Patches were the "ultimately symbol of the gang" and not to be worn by those who weren't members, he said.
"It is perhaps the most prized possession of a gang member and, because of that, they're used as trophies of war. If you lose your patch it is seen as a terrible disgrace, and quite a trophy if you take one off a member.
"So they're very highly prized, revered in fact. You can't put one on or wear one unless you are a member and while they won't impose a copyright infringement they'll do a streak version of that which will be far swifter that wouldn't be fun."
He said gangs wouldn't hesitate to remove a knock-off patch if they saw one.
"It would be peeled off you faster than you could blink."
New Zealand Police said it wasn't illegal to wear, buy or sell gang insignia but people had to comply with the relevant legislation and bylaws.
"We would also urge them to consider the potential risks of being perceived as associating with a gang," police said in a statement.
Mr Gilbert said knock-off gang insignia had been available for some time but he wasn't aware of fake patches surfacing in the public's eye.
