Life member Harry Tam has said there could be serious consequences for those who are caught wearing the knock-off products.
"Obviously this has never happened before but I'm sure if people do it, they'll no doubt find out in due course what the consequences are," he told media outlets.
"When it comes down to it, the people purchasing these are putting themselves in jeopardy.
"There's certainly no mana behind the [counterfeit] patches."
"All I can say to them is don't wear it. If you own one send it back to them to ask for your money back. It's probably not a good idea to be seen with it, with something that doesn't belong to them."
Police have also warned members of the public of the potential dangers of wearing the knock-off patches, saying they risk angering the gang as well as associating themselves with that kind of activity.
"Police constantly monitor the gang situation in New Zealand, and while it is not illegal to wear, buy or sell gang insignia, police would remind those who choose to wear it of their obligations under the relevant legislation and bylaws," a police spokesperson said in a statement.
The Mongrel Mob has recently opened up a chapter in Canada with more than 20 affiliated members.
The Mob's Canada Facebook page has more than 2000 people following it, with the Mob making regular posts of their outings.
Photos show members wearing clothes with Mob patches with Mob banners and stickers in shot.
It is believed the group is operating out of Montreal, often posting images of group catch-ups and news from back home in New Zealand.
The Mongrel Mob was founded in Hawke's Bay in the 1960s and has long had chapters not only in New Zealand, but also Australia.
