The Automobile Association believes motorists have good reason to feel ripped off when they fill up with gas.
The price of a litre of unleaded petrol has crept up again, and currently it is sitting at about $2.20.
At the same time the New Zealand dollar is trading at five-year highs against the greenback, cracking US$0.85 to the dollar last week.
The AA's Mark Stockdale said prices rose three cents a litre last week, but there was no explanation.
"It's very worrying.