Instead of paying for his ice cream at a convenience store, a thief flashed a gun at the shop assistant before making a hasty getaway on a bike.
The theft happened this morning at the QE2 Foodmarket in New Brighton, Christchurch.
Police said the incident was reported to them at 9.30am.
"A man stole an ice cream from a store and on the way out has shown what was thought to be a firearm," a spokeswoman said.
"He didn't make any threats or point the weapon and police are making inquiries to locate the man using CCTV footage."