Petrol companies are being asked to explain anomalies in the price of fuel.
The Commerce Commission has sent letters to several petrol companies, after prices were monitored in the first year of a new regulatory regime.
Commission chair John Small says he's at a loss to explain the variance in pricing.
The Waitomo Group runs more than 75 petrol stations, between Paihia and Dunedin, but it hasn't been questioned by the Commerce Commission over its pricing.
Waitomo managing director Jimmy Ormsby spoke to Corin Dann.
