Member for Grey Rowan Ramsey has written to ACCC and other relevant bodies saying Whyalla is being 'ripped off'.

He said the price discrepancies are 'just getting ridiculous'.

Mr Ramsey said the cost of freight from Adelaide to Whyalla is only about three cents a litre and does not justify the hiked price.

He said he has written to the ACCC pointing out the failure of the market to provide a competitive environment in the city.

"The Prime Minister promised before the election to fix fuel prices, all he has offered is 'Fuelwatch', which offers to compare prices and stop people reducing a price during the day," Mr Ramsey said.

" This is useless in Whyalla as there are no cheap outlets so effectively there are no choices."

Member for Giles Lyn Breuer said the differences in price were worrying.

She said the huge monopoly in Whyalla had caused the price hike.

Ms Breuer said the situation was a deadlock legally and although she would continue to raise concerns in parliament and write letters to regulatory bodies and authorities no legal action could be taken.

She said the best way to tackle this situation was for the community to get very active and outspoken.

"It is unfortunate that we cannot attract new fuel retailers into town to bring in competition," Mr Breuer said.

"One thing that can be done is that people speak out and shame the retailers that are playing around with the prices.

"Fuel companies, retailers, authorities and regulatory bodies will be forced to look into our situation to find a solution if concerns are raised by a lot of unhappy people."