Shoppers at Countdown Papakura had to be evacuated this evening when a small fire broke out in the store.
Fire crew attended at 6.15pm to find the store smoke logged said Fire communications shift manager Jarron Phillips.
"They found paper on fire in an aisle at the rear of the building," Phillips said.
"It is being treated as suspicious and is being investigated."
A man who answered the phone at the store said he couldn't speak because he "was in the middle of an investigation."