Fuel prices in the Northern Territory rose sharply during the past month.
Latest figures from the Australian Institute of Petroleum show the average price of unleaded petrol in the Territory was $1.68 last week, 10c higher than the national average.
Over the month of July, fuel prices in the Territory rose almost 3 per cent.
Nationally, the situation was worse, with fuel prices jumping 6 per cent over the month.
For the year to the end of July, fuel prices in the Territory rose nearly 8 per cent.
Meanwhile, Woolworths chief executive Grant O'Brien denies that fuel discounts being offered by major retailers are hurting competitors.
The Australian Competition and Consumer Commission has announced that it will investigate Woolworths and Coles offering shopper docket discounts on fuel.
Mr O'Brien says he has seen no evidence that the discounts have reduced competition.
"Over the past decade ... there has been no pronounced shift in volumes from the independents or other players in the market," he said.
The Service Station Association says nine independent fuel retailers closed last month because they can't compete.
Mr O'Brien says Woolworths will find alternatives if the shopper discounts are made illegal.
Full-year sales for the Woolworths group have risen 4.8 per cent to $59 billion.