"A leading economist believes fuel retailers have a case to answer as to why petrol prices remain well above the wholesale price, particularly in regional areas.
The price of wholesale fuel has eased by eight cents since its peak in early May, but the retail price has only fallen 5.5 cents in that time.
The Institute of Petroleum says prices in capital cities fell to 138.6 cents a litre, while the regional average fell just one cent to 143.8 cents a litre."