The Commerce Commission has launched investigations into the country's two big supermarket chains, after complaints about pricing and promotional practices.
The Commission is looking at Woolworths and Foodstuffs, which operates the New World, Pak'n'Save and Four Square supermarkets.
Foodstuffs and Woolworths both declined our requests for an interview but say they will fully cooperate with the investigation.
Minister of Commerce Andrew Bayly spoke to Corin Dann.
