The government will soon look into the country's major refineries and gas stations to see if they are making excessive profits by raising already high fuel prices, the commerce minister said Monday, turning up the heat on them to limit price hikes.

   The warning comes as gasoline and diesel prices are rising almost daily, which was expected as the voluntary reduction of oil prices by the country's major refineries that started in April ended earlier this month.

   "Refineries and gas stations are currently pointing fingers at each other (for the recent hikes of fuel prices), so the government will sample 500 gas stations to see who is right," Knowledge Economy Minister Choi Joong-kyung told reporters.

   The refineries had vowed to gradually return their prices to normal levels, and are now accusing private filling stations, which set their own prices, of implementing the recent spike of prices.

   Choi said the government will look into the books of the 500 selected gas stations to see if they are making excessive profits and also if they are selling any fake gasoline or gasoline substitutes in violation of laws.

   The stations that will be investigated, out of some 10,000 in the country, will likely be the ones with the highest gasoline and diesel prices, he said.

   The Ministry of Knowledge Economy earlier asked the finance ministry to lower taxes on gasoline and diesel to help prevent any sudden rises of prices, but it was forced to seek other ways of controlling prices, such as convincing or pressuring sellers to limit their price hikes, as the finance ministry refused to do so.

   The ministry was also set to raise the average price of electricity this month but has postponed the move by at least a month due to its knock-on effect on prices of other consumer goods, including fuel.

   Choi said there still is no set date for the rise of electricity prices or a decision on how much the prices will be raised.

   "Rather than saying when or how the price will be raised, I will just say the move will focus on rationalizing the electricity price system in the long term," he said.

   Currently, electricity prices reflect only about 94 percent of production costs as electricity has long been considered a public good here. (Yonhap News)