Accessorising your device with an iPhone case which looks like a hand gun could cost the user up to $4000 and time behind bars, police warn.
Overseas, the accessory was slammed by the New York Police Department who called it "ridiculous" and warned people not to buy it.
After hearing it could be purchased online and shipped to New Zealand for under $100, police here have added to the criticism.
Jason Ross, a manager at NZ Police, said "on the face of it" the phone case would be regarded as an imitation gun and police would treat it as such until proven otherwise.
"We would strongly advise against carrying such items given their considerable potential for causing unnecessary alarm to the public, whether this is intended or not," Mr Ross said.