New Zealand retailer Gun City, which sold weapons to the man accused of shootings at two Christchurch mosques that killed 51 people and injured dozens, has aroused concern with plans for a mega store in the South Island city, media said on Wednesday.

Radio New Zealand said some of those living near the proposed site were upset at the prospect of the store, sprawling over 300 square meters (3,229 square feet), along with a warehouse, office and carpark, set to open in August.

"I don't think many people will be very comfortable to have guns around their homes in a residential area," one of the residents, Harry Singh, told the broadcaster.