( dpa ) - The New Zealand government has launched an investigation into petrol pump prices to see whether the big oil companies are co-operating in an illegal cartel that is anti-competitive, Commerce Minister Lianne Dalziel said on Monday.
"It takes a long time for an international crude oil price drop to find its way into our petrol pumps and it takes a very quick time for the price increase internationally to find its way into our petrol pumps," she told Radio New Zealand.
"Those are the questions that we'll be looking at as to whether there are competitive pressures that are not being applied or whether there is some collusion cartel behaviour between the oil companies."
Dalziel announced that an independent consultant, who she did not name, had been appointed to undertake the inquiry which comes after oil companies introduced two big increases in petrol pump prices last week.
The price of the most popular 91-octane petrol is about 2.11 to 2.13 New Zealand dollars (about 1.60 US dollars) a litre in New Zealand cities, 35 per cent higher than a year ago.
The companies change petrol prices suddenly and they have risen by up to 24 cents a litre since early May, when the Automobile Association began calling for an inquiry into the New Zealand fuel market's pricing structure.
The AA wants New Zealand to adopt a regulation being trialled in Australia that forces the oil companies to give 24 hours' notice of price rises, enabling motorists to fill their tanks before they take effect.