Police say buying or selling gang insignia is not illegal, as products featuring patches pop up for sale online.
RNZ has seen blankets and plaques for sale on the online shopping website Temu, with known gang insignia displayed prominently.
The government banned the display of patches in public places last year.
RNZ has found products on Temu featuring the logos of the Killer Beez, Mongrel Mob, Black Power and the Headhunters.
Several accounts are listed as sellers for the products, but one in particular has sold products from both Black Power and the Mongrel Mob.
The origin of the products was listed as Zhejiang, China.
Some products appear to be edited, but a person who bought a Black Power shower curtain earlier this month rated it four out of five stars, saying "great, was a gift very liked".
A police spokesperson said, to the best of their knowledge, buying and selling gang insignia was not against the law.
RNZ is seeking clarity from the Justice Minister on the legality of selling patches online.
'No point buying it'
The town of Wairoa in Hawke's Bay has already dealt with gang crime earlier this year and Mayor Craig Little said he was surprised to hear of products featuring patches popping up online.
Shots were fired at houses in April, associated with Mongrel Mob and Black Power gangs.
Little said he did not think gangs would be happy to see their patches sold online.
"There's no point buying it, if you can't take it anywhere," Little said. "You'll get it taken off you straight away, and that doesn't matter if it's on your clothing or anything."
Little said, while he could not speak on behalf of the gangs, he knew their insignias were their own and not others to use.
He said the gang patch ban had made a difference in Wairoa.
"I don't think, I know it's better," Little said. "The police have told me the crime rate has gone down and people don't feel intimidated like they used to with patched members walking around.
"Overall, I think it's been a success to be quite honest."
