Pest controllers have trapped close to 20 more rats since Friday at a South Dunedin supermarket, which remains closed for cleaning and monitoring.
It comes as a new video shows a mouse scurrying across uncovered salad at Christchurch's Eastgate Countdown.
New Zealand Food Safety staff have been on the ground at both supermarkets and confirmed it has launched an investigation into the latest furry problem.
Tess Brunton reports.
