One woman had been unloading her shopping in the trolley bay next to the store entrance when she heard the commotion inside. She saw a man running out the door with the shopkeeper in hot pursuit, so pushed her trolley in front of him, hitting him in the knee.
He panicked and ran off along the waterfront, apparently forgetting his three accomplices waiting in a getaway car in the loading zone immediately outside the shop.
Mr Singh said his brother Raju chased the offender but lost him when the getaway car picked him up.
"We'd like to thank the woman with the trolley, and also members of the public who tried to chase him," Mr Singh said.
Constable Murdock, who said it appeared to be an opportunist crime, with no weapon or threats involved, urged anyone with any information to call the Mangonui police station on (09) 406-2060.