"It is good to see that the store attendant remained calm and did not do anything to cause harm to himself or add further aggression to the situation."
All three men were seen in the CCTV footage wearing hoodies and bandannas covering their faces.
They spent no more than 22 seconds in the store and are believed to have fled in a vehicle parked near the store.
Police appealed for anyone who recognised the men in the footage or knew anything about the incident to contact police immediately.
"We will be exploring all avenues in the course of this investigation, however, at this stage we believe this is an isolated incident," Mr Wilkinson said.
"We are interested to hear from anyone who may know someone who is in possession of a large amount of synthetic cannabis."
The Video Expo's Manukau store was robbed in February, however police do not believe the incidents were related.
Both cash and synthetic cannabis were targeted in the Manukau robbery.
"We would like to encourage anyone who knows something about where these products are to contact us as soon as possible."
Information can be provided directly to Counties Manukau Police on 09 213 9000 or anonymously through Crimestoppers on 0800 555 111.
